I guess if you are okay with a series of short term relationships, there is no need to change.
The problem is that relationships do change, I feel like they are intended to grow the people who are in them. In fact, many experts say that relationships exist only as a vehicle to get to know ourselves. So, those same people would argue that keeping relationships only during the initial phase is in a way ensuring that you don't grow, that you don't really ever get to know yourself and your needs that exist beyond affirmation and attention (and sex).
That said, boy I could use a rush