This is how I was feeling too. "Gameplay" is a pretty broad term. "Mechanics" gets more specific, but games are such a package deal.

Even for mechanically light non video game fare from pen and paper to board games to slot machines, people value style and aesthetic so much. It really can affect the mechanics and thus, the gameplay.

Bloodborne had great combat mechanic, but that deep gothic feel, added so much to the tension of the game it wouldn't make sense otherwise. Imagine Bloodborne's mechanics being ported to Grand Theft Auto 5. Shambling around with melee weapons and single shot guns in a modern city that was way too big and open wouldn't feel the same at all (despite being fun as a departure!)

So I'd say I'm firmly in the gameplay/mechanics camp myself. How many beautiful games have we seen that jut don't do the job with how things happen in the world. It's my major beef with the Rocksteady Batman games. Being Batman feels like a chore and beating on guys feels more like a dance dance revolution rhythm games than hard hitting Batman style combat.

Thats my take anyway. I know people adore those games though. Great post!