"Strange how much human progress and achievement comes from contemplation of the irrelevant." - Scott Kim
There are fine lines between doing something to see what can be done (and learn & progress from it), doing somthing just for marketing reasons, answering a question that wasn't asked, and answering a stupid question.
The automatic revolver was "see what can be done". The idea was tried, it worked, it didn't help, progress deemd that a dead end and continued elsewhere.
The .45GAP is mostly just marketing reasons. Yes it gets .45ACP power into a standard Glock platform - but only because it's cheaper for Glock to have one platform than two.
Extra-long flash suppressors just to make the 16" limit answers a question that wasn't asked. No legitimate question has an answer "a flash suppressor over 5 inches long".
"Double-action-only" Mossberg 590DA shotguns (to wit, a perfectly good shotgun with a stupidly heavy trigger) is an answer to a stupid question. Rochester NY police were required to switch to it after a suspect in a drug raid was accidentally shot; the overseeing council asked "how to we make it hard for police to fire their guns", and the answer was a 14+ pound trigger.