While both raids were a mess, I loved doing them with my small clan, it was the glue that held everyone together as we would do all of the raids regularly, once the raids got removed my clan mates stopped playing.
Sure, the raids were not very hard, but you actually had to pay attention to what you're doing, which isn't true for the rest of the game which devolved into nuking whole rooms with a press of a button. And I enjoyed that, it was engaging.
I'd also say that raids were the last co-op content (maybe with the exception of Eidolons) of Warframe, sure you can play pretty much every mission co-op with 3 other people, but what's the point if just a single person can finish the mission just fine? Raids required a degree of coordination, everyone had to do their job, even if it was a very simple one, that's why me and my clan mates enjoyed it I think, because we were actually playing together.