i mean i understand how frustrating it can be when people use phrases like "because reasons", because it really just asks more questions than answered, while i'd prefer to just know those reasons. especially in arguments since being vague and dodging the problem is just going to make the situation more difficult.
although while thinking of the phrase i don't mind if it's said with the intent of showing that they themselves don't know why. not in the sense of a scapegoat answer, but legitimately communicating that the person doesn't know why. for example if someone was venting about something embarrassing they did, and used it like "I thought it was a good idea to do (blah blah blah) because of reasons, ugh why". I'm not too inclined to find that sort of use too annoying. But like everything, it's all about moderation.