He doesn't need to be sarcastic. It's just the same effect if he's sincere. Even if edw519 is sincerely complimenting Joel on 'disguising a PR piece as an objective "how to"', that's not going to be a welcome comment if Joel didn't feel he was writing a PR piece, let alone disguising it.
A sincere compliment for doing something you wouldn't do intentionally doesn't make the recipient feel good.
Absolutely. I especially "use the general tone of the person writing if you happen to know them?". And if I don't know them... all bets are off and I read as _I_ would use those words.
A sincere compliment for doing something you wouldn't do intentionally doesn't make the recipient feel good.