why are you asking this question? justification of your own actions or a potential chance to throw stones at so-called hypocrites?
people choose not to attend church -- for a period of time when they are going through something personal or some never become part of a fellowship. lots of different reasons but you can't draw some generalized conclusion from that. i have gone through those phases myself.
the bible is pretty clear that IF we don't belong to a fellowship body, we are being disobedient and missing out on an essential part of the faith. not salvation. this is the way that christ's body is realized on the earth...different gifts and parts working together. so not only do we miss something personally when we don't have fellowship, but the world misses something too. think of what a powerful witness it could be if all of us lone wolf christians became part of a fellowship.
i think a more important question for those of us NOT attending a body is HOW are you getting fed? do you read your bible? do you pray? do you listen to sermons or teaching? if we DON'T belong to a fellowship, DON'T worship with the body, AND DON'T get fed....how exactly are we supposed to become like Christ?
Your question assumes that every conservative is a Christian. Many of us are not.