Sure, theft still happens, but I don't see why home theft wouldn't be reduced by the presence of CCTV or other video surveillance.

CCTV doesn't work well when people feel like nobody is going to bother to check its footage (e.g. pocketing a $2 drink from a big-box department store). But when it comes to homes, there are much higher chances of captured footage being used and examined, so it may cause opportunistic burglars to look at other houses instead.