Two entirely different services/concepts. I'm sure were all bitcoin fans here but something tells me you would rather use paypal for purchases on ebay to avoid being scammed and I'm also sure many of us would prefer to use bitcoin when we want to be fairly anon or make purchases on the darknet etc. Both services have pros and cons and are better/worse in certain circumstances but bitcoin is certainly an alt option outside of the mainstream but at the moment paypal ic accepted on pretty much most online retailers where bitcoin is the opposite.