Vegans choose to abstain from animal products, not that they "don't want them."

The reasons might be environmental, ethical, moral, or religious, etc... Not important, just that a vegan or vegetarian is simply someone who did a cost-benefit analysis where, to them, the costs of meat (environmental degradation, massive suffering, personal guilt, my-god-said-so, whatever) outweigh the benefits (taste, convenience, social acceptably). That's merely it!

It's not cognitive dissonance to want to enjoy some of the benefits of something without some of the costs - that's what vegan "meat" (at least attempts) to do.