I had a situation recently where someone accidentally took my bag thinking that it was theirs, and they eventually came back to baggage claim about 15 minutes later after they realized it.

If you think about it, there's a pretty serious security issue there. Someone could walk into an airport with a bomb in a bag, toss it on the baggage carousel while nobody is paying attention, and then walk out. It wouldn't get noticed by security looking for unattended baggage because it's expected for there to be unattended baggage there.