Well, it's probably not like people want to do 1000 kitchen renderings in a row but it's their business, simple as that. If you could choose what you'd like to produce, I'm certain people would have more diverse stuff in their portfolio. So, when you're specialized in interior renderings (maybe even in kitchens) and earn your money with it then you'll probably also want to show your work somewhere, even if there are already hundreds of other peoples work there (vray forum, evermotion, corona, ...) .
It's the exact same thing in other fields and their communities (like game models, sculpting, texture painting etc). 95% average non-commented stuff (even if it's really good) and 5% outstanding creative works where people actually write a comment to.
