Yes, I do it more often than not. I usually try to clear even routes I don't find interesting and what can stop me from doing it is only bugs, extreme boredom, irritation with characters or strong desire to play another game.
Unless the story is really bad, i try to at the least get the main route done.
Once i get one ending, most of the time i stop here. I don't bother with the other endings except if it's a "bad ending" that doesn't really satisfied me (Like when one of the character wich i really enjoy die)
Lately, i read nothing but kinetic Vn, so it wasn't really an issue