I don't comment on every entry, but I do read them all. I don't care if you don't comment on my entries often. I'm just here to entertain you. It's ok if you're only here to find something fun to read! I think people over look the value of that aspect of LJ.
Another thing.. life happens. People come and go. Users that have been around know this well and are less likely to throw a tantrum about someone being on hiatus. These are the kinds of users I'm looking for. In layman's terms, attention whores need not apply.
I'd rather have someone that posts and comments when they feel compelled to, not because they feel like they must. I feel like these types of users are much less fickle and are more likely to put in the effort to get to know their audience.. rather than going on deleting sprees because they're attention starved.
Comment here to be added.