I think a lot of times it is just preference, and I understand what you are saying.
I cross my towers over at 60 though which is pretty much the very lowest you could go with a bookshelf and when I play 2ch I run them full range because they extend into the 30s and I dont need a sub.
That being said I have towers in the dedicated HT and bookshelves upstairs.
A lot of people buy fancy bookshelfs, fancy stands and end up paying as much as a decent set of towers that would take the same amount of real estate.
Think of speakers like women, they come in all shapes, sizes and prices...you get to pick what you like best!
