Good heavens!! I admit I am a bit compulsive about the care of my instruments but my oldest "no name" guitar that I have owned since high school (and I graduated in 1973) does not have finger indentations on the wooden fretboad! What the heck did hey DO to those guitars?!?!?
Think some of them must have hands like a grizzly bear.
I've heard it called "gorilla gripping". I grip pretty hard and I've worn out frets on a couple of guitars, but I've never actually indented the wood itself. Dunno how hard you have to play to do that, especially since I'm a pretty aggressive player and even I'm not accomplishing that.
I know over time anyone can do it, but we're talking guitars here that can't be more than a year and half old, 2 years tops.
===================================== One Alvarez in the hand is worth two Taylors and a Martin in the guitar store!