I am only an amateur in all the relevant areas of expertise, but I have invested quite a bit of effort trying to make sense of these controversies. I have to say that your post is very confused, and you seem to lack familiarity with many important facts that would have to be considered before pronouncing such a sweeping judgment.
The lack of obvious correlations between genes and phenotypes implies only that the phenotypes in question are not determined by the genotype in a simple way. If they are determined by complex interactions between genes, then straightforward association studies won't detect this connection. To make an imperfect but relevant analogy, if you took the machine code of various computer programs and did a statistical association study between these codes and the resulting behavior of the computer, while being ignorant of the way the instructions are actually decoded and executed -- as we are still largely ignorant of the relevant biochemistry, which is also far more complicated -- you could easily end up with no observable correlations.
Similarly, if some trait can be influenced by environmental factors strongly and rapidly, it is still a total fallacy to conclude that it is therefore determined purely by environmental factors. To take a trivial example, nobody disputes that hair color is highly heritable, but the development of cheap and convenient hair dyes has changed the average hair colors in the population dramatically. The behavior of computer programs is highly dependent on what you give them as input, but it doesn't mean that the program code is irrelevant.
As for heritability studies, you are certainly right that there is a lot of shoddy work, and by necessity they make a whole lot of wildly simplifying assumptions. If there existed only a handful of such studies, one would be well advised not to take them very seriously. However, the amount of data that has been gathered in recent decades is just too overwhelming to dismiss, especially taking into account that often there have been considerable ideological incentives to support the opposite conclusions.
On the whole, you are making a wholly unsubstantiated sweeping conclusion.
This is hardly news, but this Guardian article reminded me of it - genes are really overrated, both among unwashed masses, and also here on Less Wrong.
I don't want to repeat things which have been said by so many before me, so I'll just link a lot.
Summary of evidence against genes being important:
Summary of evidence for genes being important:
And there's nothing more. Decades ago, before we had direct evidence of lack of correlation between genes and outcomes, it was excusable to believe genes matter a lot, even if it was never the best interpretation of data. Now it's just going against bulk of the evidence.
And in case you're wondering how could twin studies show high heredity when everything else says otherwise, I have two examples for you.
This one from a critique of twin studies by Kamin and Goldberger:
"A case in point is provided by the recent study of regular tobacco use among SATSA's twins (24). Heritability was estimated as 60% for men, only 20% for women. Separate analyses were then performed for three distinct age cohorts. For men, the heritability estimates were nearly identical for each cohort. But for women, heritability increased from zero for those born between 1910 and 1924, to 21% for those in the 1925-39 birth cohort, to 64% for the 1940-58 cohort. The authors suggested that the most plausible explanation for this finding was that "a reduction in the social restrictions on smoking in women in Sweden as the 20th century progressed permitted genetic factors increasing the risk for regular tobacco use to express themselves." If purportedly genetic factors can be so readily suppressed by social restrictions, one must ask the question, "For what conceivable purpose is the phenotypic variance being allocated?" This question is not addressed seriously by MISTRA or SATSA. The numbers, and the associated modeling, appear to be ends in themselves."
As the final nail in the coffin of heredity studies:
The Body-Mass Index of Twins Who Have Been Reared Apart
We conclude that genetic influences on body-mass index are substantial, whereas the childhood environment has little or no influence. These findings corroborate and extend the results of earlier studies of twins and adoptees. (N Engl J Med 1990; 322:1483–7.)
Or as paraphrased by a certain commenter on Marginal Revolution:
IOWs, the reason why white kids of today are much fatter than white kids of the 50s and 60s is due to genetic influences and environment has little or no influence
To summarize - heredity studies are pretty much totally worthless data manipulation. Once we accept that, all other evidence points for environment being extremely important, and genes mattering very little. We should accept that already.