Nah, I finished up to now something like 60 visual novels and the h's in them were totally unimportant for the story.
And if they were necessary, then because of a totally stupid facepalm reason. (f/sn, wanko to kasurou, demonbane)
I like h's when they're placed at the right point of the game. They should be something like a reward for playing a route.
I also dislike the "confession->10sec later->kiss->10sec later->sex" way of handle things, it feels just wrong.