That depends on whether you're running a Linux box at home in a "reliable enough" way to be functioning as a server. And in the example you give, as your primary machine as well. While I realize that many /. users do this, I would certainly say that most people don't.
I actually stopped doing it several years ago. I concluded that I have to maintain enough complex systems at work; I don't see any need to be a sysadmin for a complex system that requires nonstop patching and understanding of 30-year-old system internals at home, too. Plus the desktop environment was frankly primitive compared to modern machines. So I ditched it and started running OS X. (And I should say that I'm an experienced Linux sysadmin and engineer professionally, so this was not the "I don't know how to use it and it appears to have been designed by badgers" issue)
It's definitely true that, if you're already doing all of the work to run your own system at home, adding a DNS server isn't a big deal. But that's really a hobbyist thing to do. If your home system is primarily for the purpose of getting things done, rather than for playing with systems, it's an enormous amount of extra work. Yet having faster DNS lookups is still a win.