Still, to do this day - fork or not, I can not for the life of me understand why anyone would allow any exchange to hold their keys.

BTC's still so new on the market - sure, there are some pretty trustworthy ones around, but I still think the market is too new to really cull out the good from the bad. Please, just learn the basics and hold onto your own keys! (get to know paper wallets, redundant back-ups, etc. etc.)