Some of the things on that list could be fine, by the way. I really like this winged sofa, this winged sofa and I don't mind this vintage two-toned sofa, so if your sofa fits into any of those categories and now you are crying, know that I'm speaking in generalities and it still depends on the sofa (and if you actually own one of these, I'm sorry!!). Also some of those could be fine if the fabric was different, or if the legs were updated (see me backtracking?? I feel bad already).
I started to think about why people buy generic/bad sofas and I think it's two different reasons: cost and availability. These are sofas that are generally inexpensive, and don't have a long lead time — you can get them in under a week, not the usual 8-10 weeks that even Pottery Barn and Room and Board have. They tend to be from those 'furniture liquidation' or 'Dave's Furniture' stores that are in every town. You can actually go in and sit on them, make the decision together, get it within a week, etc. I get it. I can't really solve that last problem — those stores just need to start carrying better furniture.
But, until stores across America start selling better furniture, I wanted to present to you some other super inexpensive options that you can buy online and have shipped to you. These sofas are all under $600. That, my friends, is crazy.