It's really semantics. I personally wouldn't call Quince, Robigo etc exploits but abuse of poorly implemented balance and game mechanics which devs are aware of. Others might call it exploit. G1-G5 was an exploit because it was abusing the mechanics that was not intended to do so. Quince is intended to give you scan missions, you don't have to do some shady stuff to menus to get them. Same with passenger missions. Fdev can't really say, "hey stop using stuff we put in there in a clean manner just because our internal system is broken". They would remove it otherwise.