they would teach him flying techinque and proper decision making, which he clearly lacks.
Yeah, gliders don't have much to do with stabilized approaches in a jet transport, go-arounds or balked landings. It's a completely different ball of fish.
Also, you will find that skill deficiency of an airline pilot is rarely, if ever, solved by sending said pilot to glider school. Finding root cause and creating a bespoke training training plan with simulator and line training is a much better tool.
its not the fact that he pressed the button, it was all what preceeded that, stream of bad airmanship and lack of command of situation, let alone no CRM.
Anybody can get themselves to a point where approach becomes unstabilized and I believe most of us have been in that situation at least once. It's quite natural to try and "salvage it" but once you give up, it's the correct execution of the go-around/balked landing which counts, and was not done properly here.