That's true, but if you don't download much, then it doesn't take long to defrag. Heavy downloaders should run it at least once a month, and even casual users are encouraged to do it every 3 months. I don't understand what it is about the default defrag, but it apparently isn't as thorough as it should be. JkDefrag is free to use, light enough to where you don't even have to install it, and seems to be better (I've noticed an improvement in my Windows load time).
I never said I used it for cleaning my registry (I agree, there's no point to it). I just use it for cleaning cache and temp files. It's free, doesn't negatively impact my performance, and it helps a little. Just make sure it doesn't start with Windows and disable active monitoring.
Confession: Me too. When I tried to get a friend into VNs, he said he didn't wanna take the chance of getting hacked for some dumb reason. So I just shrugged it off and left him alone.