Of course it's not stupid if that's what you like to do but you're being hypocritical. You think it's loserish at a certain age just as some people see it loserish at any age, including 20s. If it's something you enjoy, then you should do it.
I'm 33 and go out(to clubs) about once a week. The only reason I don't go more often is because I am older and my body physically can't handle it, recovery time is a lot longer and I waste a whole day such as today. I have to make my work up on the weekend. In my 20's I was good by noon. I went out last night to watch the game with a friend who is from Miami and a huge fan. Then we went out to celebrate, naturally. He was happy as hell and had money to burn. We went to a strip club with a couple of his friends..then I ended up staying over and came back home this morning to go to work. I guess that's considered wild but I only do this once in a while(as in a few times a year).
I still go to Miami every other month mainly to party and hang out and went to Vegas over Memorial day weekend, went to a pool party everyday, including rehab on Sunday. It was awesome! Yes that experience would not be there if I was in a relationship(girls trips), and I am glad I was able to experience this before. Now I just enjoy it until I meet someone. I know married couples that still go to Vegas and travel a lot together, but obviously it's a bit different.
It's something I enjoy and don't see stopping anytime soon just because I'm not in my 20s. It's not something to get out of the way. I will continue until I meet someone and then modify, I would like to do almost the same things with him and our friends. I see other couples and groups(at my age) with similar lifestyles. It's really not that big of a deal, just a different lifestyle. I wonder if I'll ever get bored of it, I imagine it will happen one of these days but not anytime soon. And obviously if I ever have kids, things would change.