Stopping the flow of gameplay with pointless bullshit plot that you don't care about because it's a fucking Pokemon plot and it doesn't matter. The only character I looked forward to seeing was Colress, and that's because his music was cool. This goes for the entirety of gen 5, and I hate them for it. Get to a new city and want to explore? NO FUCK YOU WE HAVE SOME PLOT. Don't give a shit about the PWT until post game? NO FUCK YOU GO THERE BECAUSE PLOT. Want to ignore the Pokestar Studio's existence? BUCKLE THE FUCK UP BECAUSE PLOT IS ABOUT TO HAPPEN.
This can be said for any game in the series, but at least in gen 3 the story bits weren't long winded and only happened when they were absolutely necessary. Gen 4's were riding the line, but ultimately they involved a bit of gameplay, like running after the space autist with the bomb. Gen 6 had characters that were actually kind of fun to listen to, and where they could have easily stopped you every third step to tell you something, you could run past them on routes while their speech bubbles fade off into the distance.
So yeah, fuck Gen 5. I want to explore, not be stopped every five steps.