I'm not really a fan of that guy at the party who pulls out a guitar, but I'm always down to play some Guitar Hero with other skilled rhythm gamers.
Is it because he makes you feel bad that you wasted your time playing video games instead of learning the real guitar?
It's not about feeling bad or jealous. It's that playing a guitar in a room full of uninterested gamers would be as awkward as playing guitar hero in a party where nobody enjoys casual games.
Unless you go pro, these are all leisure activities. Some are older than others and some get more traditional respect, but why is that important? I choose to learn an instrument, but I don't see an inherent reason why learning an instrument is better or worse than video games.