By the Rules of Golf, it's not just an etiquette point but may be an important psychological part of the game. To concede or not may be used for various purposes, including to disturb or annoy the opponent. It's completely at the opponent's discretion (Rule 3.2 b):
I had a guy named PhilLava cry like a lil woose when I didn’t concede a put to him (I was actually typing and couldn’t see concession button, but irrelevant). Calling me a F’ing Loser.
Sat there and waited for the timer to go down to a couple seconds before putting, then throwing a hissy fit. Seriously, like he was entitled to it, lol.
All I could think is what a weak pathetic character this is. I couldn’t imagine becoming so irate with an opponent because they didn’t GIVE me something for free. How freaking feeble do you have to be to do that. Just putt the ball.
I couldn’t care less about getting a concession for a one inch putt. It’s a gift not a rule. As far as I am concerned if I suspect a player I don’t know is expecting a gift, they can be sure to never get one.