But if you aren't serious about staying together with your partner, e.g. actually planning to break up with him/her in a few months, then what's the point of devoting your time and energy for him/her?
If I sound aggressive I apologize. I love to convey my thoughts on discussions such as this. But I do not think there is anything wrong with early relationships. Not even touching on the sexual aspects (which would probably hurt my case), I think the experience is something people should have entering that phase in their life where they are looking to settle down and get married. I don't feel it detracts from the lives they're already leading, and in the cases where it does, they should make the decision to adapt, or break it off.