Friends are certainly not expendable but the reality is, there's just not a lot of time for them during the week. But I don't think this is a "startup on the side" thing; most of my friends who are married with kids don't hang out much anyway. In my particular situation, Saturday nights and Sunday afternoons and evenings are usually when we'll hang out with other families. But again, I think that's more a function of having young kids than of doing a startup.
Funny thing is as I get older and most my friends start having families, I end up losing friends. Being single sucks because they rather also hang out with other families too.
