Every hard content will be faced with a backlash. Similarly old-school fans like challenging content.
Suramar was actually the first max-level questing zone for me. It felt very grindy. You just completed quests and hoped that they would stop. I hoped that we would have taken over Suramar entirely, but that didn't happen.
It was good zone and something that makes Legion special. Hard to say with 2017 goggles whether it was too grindy.