I've never seen an episode where they were depicted in actually doing work, just in talking about their social group and the character interaction. They could have all been sitting in a coffee shop or bar for all of the links to their job it had. Whereas SV does have content about their life outside of work, a lot of the comedy comes from their "jobs".

I also really don't think the BBT people are depicted as genius'. One episode I do remember is when one of them was struggling with a physics problem with electron behaviour. He finally solved the problem that had been plaguing him (a 'super smart' physics researcher, because he started thinking of the electrons as waves, and not as particles. Which any 16(17)-year-old physics student would have realized in about a minute.