When I first did CM, along with a few other people new to the dungeon, someone said "Looks like it's gonna be one of those runs, lol." because people were watching cutscenes.

This was in September 2013; the game hadn't even been out a month yet. So yeah, it's basically been present in some form (although my particular experience wasn't overwhelmingly negative) since the beginning.

Anyone doing Main Scenario Roulette really shouldn't expect everyone in the run to have cleared it anyway. Maybe back when it was a great spot to farm Philosophy tomes, I could see being a tiny bit miffed about waiting around every odd run (still silly to get mad about, but more understandable). Today, there are a ton of options for getting tomes, and with a greater chance the people you're running with have cleared those dungeons before. I skip Main Scenario Roulette quite often in favor of something quicker, and when I *do* queue for it, I fully expect there to be first timers.