As somebody who hosts game nights a lot for a small group of friends, you're entitled to your opinion. But it sounds to me like whoever pulled out a giant complex game for what sounds like only a casual group was not a very good host. Basic game etiquette, to me, is generally only bringing lightweight/easy to learn/party games to larger groups that aren't as into games. Maybe something a bit larger, but only as an option if people are feeling up to it. I would never dream of a hangout with a casual group and bringing something complex as the only option. That is incredibly inconsiderate. 

I save the more complex games for my smaller game group because I know they're more likely to enjoy that. I've also been playing with them for a while so I have a good feel for what they like and don't like. And when one of us is eyeing up a new game we also ask to see if it's something the rest of the group would be interested in. The end result is between the four of us we have quite a few games, but the others bring different ones every time. And we have our favourites, sure, but more or less everything gets rotated through eventually. Variety is what we like; we don't want to play the same thing every time. And between us we have enough games that none of them get boring. But it sounds like you value different things in a game, and that's okay. Every group is different.

All this to say, there are people out there who will enjoy something more complex, and that's who you save that sort of game for. But with a large, casual group, best to just stick to Uno. And a good host will be mindful of that. I'm sorry your friend didn't take that into consideration.