Because it's a waste of time going through a pointless process that you don't need to do? Seems like sound logic to me.
If you want to install a kernel or some sort of theme or whatever, then sure, otherwise if you're just doing it just to do it there's literally no point.
There are some nice features to rooting, but if elecro doesnt have any then yeah, he shouldnt
I planned on rooting my phone when I got it, but after a couple of months, I was convinced I didn't need to, as I had pretty much every feature I really needed.