If someone commented my healing I'd stop listening to them, I'm a healer most of the time and that's something I know how to do efficiently.
But well if someone commented me on my soon to be 50 monk or summoner I'd gladly listen to advice as I'm not even sure if I'm doing right.

then it also depends on the approach "Hey Kiara if you use that instead of that you'd keep up greased lightning easier" or "Your rotation is wrong!"
Unfortunately most ppl who do comment go with the 2nd one