Found Cat

This here beautiful cat has been handed in to the shelter as a stray, and so far unclaimed.
It is part of my job to take photo's of the cats that come in and advertise them on a few websites as found to hopefully find the owners, sad part is most of them dont get claimed yet they are perfectly friendly, lovely and healthy... so my question which I would love answered is how they end up like this??
The good part though is that they will end up in our adoption and go to loving new homes all desexed and micro chipped so that this wont happen again :)