>[You're implying] he's nothing special and that anyone who can't also do this type of coordination and time keeping isn't a valid musician.

Almost none of that was implied -- that's all stuff you're bringing to the table. /u/audiate's comment was really smartly worded to praise the musician while explaining how a mere mortal can eventually pull this type of thing off -- i.e. how it's not actually "unreal" or unattainable -- and did not imply any kind of judgement on you or any other musician. Even before the edit, and especially after.

The advice they gave is actually the absolute best thing to fight that negative attitude -- the people in this subreddit aren't superhumans who we should pretend don't exist, but rather they showcase what is possible for anyone through enough training, repetition, automation, etc. The only part that was possibly implied was that he's "nothing special", in the sense that he's not hacking or anything, and people can learn to do that. :)

The comment definitely didn't include the words "valid musician", and I think you'll find most people who want to create more musicians don't use phrases like that since it implies that some music isn't valid! I hope you don't think that way.