Late caffeine

I don't know why there are so few coffee shops open past nine-ish.  I always like/want to go out for coffee anytime from 10pm-3am, but finding somewhere to cater to my needs isn't easy.  I know I'm not the only one who thinks a business of this sort would be a good idea; more than once I've been searching around town (Charlottetown) with a group of friends looking for somewhere to sit, talk, and have a coffee late on a summers night.  Why do they all close so early?  It took me half an hour to find somewhere to get a coffee last night, and it wasn't even 10pm.