Fake meats are purchased by non-vegetarians all the time, in fact, I'm pretty sure non-vegetarians make up most of the market for these products. There are a lot of people that try to limit their meat intake, people that are okay with some meat but would prefer to avoid others (usually beef/pork), etc.
Don't think there is such a thing as a "cruelty free" product but that is another topic. I just don't think it makes sense to blame vegetarians for the lack of vegan options, if there was solid demand for the products grocery stores would happily offer them. And I don't think vegetarians should be mortified that their shopping habits may have an indirect effect on some vegans, after all, what are they suppose to do?