The issue a lot of folks had (myself included) was that - especially when cross-realm - it just made grouping up seem like effectively playing with bots you’d never see again. The old style despite (because of?) the inconvenience tended to strengthen player bonds on a given server.
Of course, this is all much easier to do when you have loads of free time on your hands to dink around and get into random situations while waiting for a group to form, etc. The form in which I most enjoyed WoW is not a form that is at all convenient to my married, kid-having older self.