Do we English or French speakers really suffer compared to Spanish or Turkish speakers because our writing system is far more illogical? Recent economic and cultural history might suggest otherwise. Look at all the waste and nonsense around the German spelling reforms – whose life has improved because of it? China seems to be doing pretty well right now, so what's the issue?
And many of the comments on Victor's post itself expressed similar sentiments; thus Rivers4:
Gosh, how will China ever become the world's second largest economy with such a cumbersome an inefficient writing system?
In fact, you could make a case for crappy and hard-to-learn writing systems being positively associated with economic and cultural success. I'd be willing to wager a substantial sum that if you found a way to quantify unmotivated complexity and uneccessary difficulty of learning, the correlation with measures of economic and cultural success would be higher than (say) the correlations of phoneme-inventory size with number of speakers or distance from Africa.
There are some simple factors that will guarantee such a correlation: national languages that were recently reduced to writing tend to have historically shallow and rationally-designed orthographies; and the countries for which this is true tend to be relatively poor and underdeveloped, simply because otherwise their literacy traditions would have started many centuries earlier. In some cases, like Turkish, special circumstances permitted a recent and radical orthographic reform. Spanish seems simply to have lucked out, by having a fairly shallow and transparent system to start with, and then undergoing relatively few orthographically-opaque sound changes. But around the world, countries who came late to the table of literacy tend to have relatively transparent and easy-to-learn orthographies; and the same countries tend, for roughly the same reasons, to remain relatively undeveloped economically, to have relatively little cultural influence outside their borders, and so on.
You could go beyond these trivial historical associations, and make an argument that an unnecessarily complex and hard-to-learn writing system is genuinely and causally a Good Thing from a political and economic point of view. According to this story, a crappy orthography — in a society where literacy matters — creates a meritocracy based on verbal aptitude and the willingness to work hard at difficult and arbitrary socially-prescribed tasks. Mastering the orthographic system is a necessary (and sometimes even sufficient) condition for economic success, and this tends to offer a path out of poverty to the bright and ambitious children of the masses, and to create a handicap for the most lazy and stupid children of the elite. You could point to the Mandarin system in Tang-dynasty China, or the English "grammar schools" back in the days when they taught Latin and then a standardized form of English.
I'm skeptical that this argument remains valid, if it was ever valid to start with. For one thing, there are now many gatekeeper subjects that are more intrinsically useful, such as science, history, and math, (And of course we've levelled the global playing field by making it necessary for everyone to learn English, which has the third-worst orthography among major modern languages, after Japanese and Chinese.)
In this context, any possible benefits of a crappy writing system are massively outweighed by the very real social costs. Becoming genuinely literate in Chinese characters takes up a significant portion of primary and secondary education. Accurate statistics on functional literacy in Japan and China (as opposed to self-congratulatory propaganda based on spurious definitions of "literacy") seem not to be available; but the available information suggests that significant fractions of the population never reach the goal, or lose the ability even if they once gained it. (See "Japanese literacy: Back to the future again?", 12/25/2006, for a survey of some of the facts.)
Those who do reach the goal waste thousands of hours on the task. And in the case of Japan, the writing is one of several factors that will make it very difficult for the Japanese to deal with their aging labor force in the most obvious way, by immigration.
In the case of English, the social and individual costs of our crappy writing system (compounded by bad teaching methods) are well documented. I'd summarize the studies I've read by estimating that nearly two thirds of American children find it difficult to learn to read, and at least 20-30% fall behind to the point that their ability to learn other subjects is harmed.
And in "Ghoti and choughs again", 8/16/2008, I pointed out that Philip H.K. Seymour, Mikko Aro, and Jane M. Erskine, "Foundation literacy acquisition in European orthographies", British Journal of Psychology, 94:143-174, 2003, found that reading error rates among first-grade school children are many times higher in the UK than in other European countries. In their study, only Danish had error rates even close to half as great, and the error rates for correctly decoding words in French, Greek, Italian, German, and Dutch were reported to be less than one-tenth as great as in English.
Seymour et al. suggest that this is because children learning to read and write English face a double problem: complex syllables and opaque letter-to-sound correspondences.
Whatever its causes, the handicap is well documented. It's true that we Americans (along with the British, the Japanese, and the Chinese) have collectively managed to overcome the handicap of our crappy writing system; but this is not evidence that the handicap has paradoxically done us good.
I should add that the Japanese, Chinese, and English writing systems do share the advantage of offering to those who have mastered them certain clues about morphology and etymology that would be missing in a shallower and more phonetically transparent system. The question is whether this is really worth the cost. And the answer, of course, is that question isn't worth answering — the chances of significant orthographic reform are indistinguishable from zero, at least in the case of English, and so the real question is whether or not we'll compound our curse by bad reading instruction.
Finally, there's a partly-separate issue about whether an orthography is lexically consistent, in the sense that the same word is always spelled the same way. This overlaps to some extent with the question of how much importance is given to morphology and etymology, but even a relatively shallow orthography can be more or less lexically consistent. Even in a relatively shallow orthography, however, lexical consistency is not easy for writers to achieve, because of pronunciation variation due to dialect, register, and the phase of the moon; because of the treatment of foreign loans, including foreign names; and because of the frequent cases where people are unclear about which words are which.
In any case, although it's plausible that lexical consistency is a virtue, I've never seen any evidence for this view — the catch-as-catch-can Elizabethan spelling system doesn't seem to have held Shakespeare back.