No idea why you think the BG devs were not aware and somehow were allowing the bugs and exploits unintentionally. Players were reporting those on the forums. The devs simply didn't bother for the most part, instead they focused on things like the bonus merchants with even more overpowered items. And you've demonstrated yourself why such a design strategy works, because most players don't even remember them after playing the game. Just like most players didn't care that their level one character survived that kobold arrow in BG1 because of an in-built cheat.
