All true, but you'll find a dremel is very handy to clean fret slots on a bound fretboard (if you don't want to take the binding off of course). I never said it's superior to a hand saw for unbound boards either, it's just commonly used that way. The fret slots hold the bit in line, so as long as the tool isn't going warp speed with a super sharp bit you won't lose control and mar the fingerboard or anything. Also, it should be said that you wouldn't hold the tool by hand, you'd use the router baseplate so that the slots stay a consistent depth.
Actually, I've done thousands of fret jobs, and usually I'll use a hand saw too. But when you run into a guitar that's had its frets glued in with epoxy or whatever, it's just a lot less work to use the dremel. Anyways, it works for me.
