AR URF makes the rift fun.
I don't like the rift in general, but urf is fun regardless. So for the first time in years, I actually like the rift. I know if is almost over, but the queue times are still really low. People like playing urf more than normal modes on the rift. If click rates show how popular a mode is, then urf is way more popular that regular normals. Queue times are less than coop vs ai for cryin' out loud.
Sure, there are some people that won't like that other people are having fun other than how they have fun, but hey ... there are more people interested in playing urf than any other mode.