I think this is where the disconnect is. It's absolutely critical on clean playing, more than anything. You will hear every little issue from sting noise to the different velocity on each string. Play an arpeggio with a clean tone and see if all the notes are the same volume. I would almost guarantee they aren't.
As far as palm muting goes I've found, and lots of really really good players have noted over the years, it's a very instinctual thing , you will gravitate towards doing it almost subconsciously. Your palm on the bass strings, your fingertips on the little ones will start to fall in place.
What Ed is talking about though is his philosophy with his rig though, which is a totally separate subject. Being a guy who straight piped his guitars into 100 watt Marshalls for ages, I agree with his take in general. His wasn't nearly as out of control as Billy Gibbons in the Eliminator era. It was so uncontrollable the had to record one phrase at a time.