Side quests are meant to be a side thing.

If you reward the players too much EXP, they will become a main thing. And then we'll all be doing crummy fetch-um kill-um quests for the rest of our digital existences (See: World of Warcraft).

I'd rather my sidequests be more interesting and entertaining. You know, rewarding me with fun rather than points. Currently the bulk majority of sidequests are pretty hum-drum, and I think you wouldn't be posting this if that wasn't the case.