I think there are probably as many answers to this question as there are vegans. :-)
I've been vegan for about 17 or 18 years, and I actually do make a homemade tofurkey for Thanksgiving every year. My kids nicknamed it Mount Vesuvius.
I actually love the store-bought Tofurkey gravy, except when they changed it and started adding mushrooms, because I hate them. I sitll buy it and use it for Thanksgiving rather than making my own (which I used to do), and just pick out all the mushrooms.
I don't buy it or eat it often, but I love the store-bought Tofurkey, too. If you cook it right, it's tender and delicious. The key is to baste it well and cover it tightly while it's cooking. Obviously it's not everyone's cup of tea, but everyone in my family likes it--including my husband who is a meat eater (but he will eat almost anything).
Besides the homemade tofurkey, I make the same stuffing that my mother always made except that I use a small amount of olive oil instead of tons of butter. I also cook squash (often stuffed squash), make mashed potatoes, and we have apple pie or something along those lines.
If my kids weren't so stuck on the tofurkey, I'd probably just make stuffed squash and mashed potatoes and other veggie dishes.
I also sometimes make a gluten roast which I love and would work for a big dinner like this, but I don't think I've ever made it for Thanksgiving.
I don't think of the fake meats as substitutes for meat. I sometimes make a sandwich with just veggies or veggies & hummus, but sometimes the fake meat slices fit nicely on the bread. I doubt they taste like meat--just something convenient for a sandwich--same with veggie burgers. I don't like the ones that look or taste too much like meat, but otherwise, they are something convenient to put on a bun--especially if going to a barbecue with non-vegans/vegetarians. My son was raised vegan and he loves the fake meats. For him they're not a substitute for anything.
I think everyone becomes vegan for their own reasons. I've been a vegetarian for about 24 years, and have been vegan for about 18 years. I became vegan for health reasons and stuck with it for health reasons for 18 years. I think it stuck. ;)
That said, I love the author's cookbooks.