I was a player in a group that all took things seriously and roleplayed our characters to the best of our ability. That group unfortunately fell apart and I've started up a new game with a different group of friends, this time as the GM.
Unfortunately, while my last group was full of people who really wanted to roleplay, this group has more of a beer and pretzels mentality. While there's nothing wrong with that kind of player or campaign, it's not the kind of game I want to GM, and I'm hoping to find some way of dealing with it. I've thought of a few solutions myself but wanted to put this out there to see what comes up. The solutions I've thought of are listed below.
I could set up a new group with players that I know want to take things a bit more seriously.
Cross the streams
Some of the players from my old group could come and mix with this new group. The GM from my old group (who's much better at this than I am) could run a campaign, and the more serious atmosphere might rub off on the new players. Roleplaying is rather embarrassing after all, and seeing that the other players are into it can help overcome that feeling.
Channel the gaming
The players don't want to seriously roleplay, creating characters with joke names and absurd backstories and motivations. People play tabletop RPGs for a number of reasons, and while it's more complicated than this, for the sake of the question I can boil that down to players that want to play a role and players that want to play a game.
These players want to play a game more than they want to play a role, so I could run a campaign with a more gamey setup. There's an XCOM campaign I've wanted to run for a long time now, and I could use that to get them engaged. With lower focus on characters and an explicit combative tone to the campaign. If roleplaying doesn't engage them, a serious and uncompromisingly difficult enemy might. The players might joke around and make a squad full of "Rod Thrashcocks" in the beginning, but when they realise that the aliens are taking things seriously they might do so as well.