No idea but if I have to guess people get bored. They create a pet and sometimes it is hard to come up with a name and all the good ones are taken....so I think they just come up with anything. Then they get bored, get rid of the pet and start over again.
Lately what I have been doing to try and help some of these poor souls. Is adopting them, zapping them with the lab ray until I get a cool color and then putting them back in the pound to get adopted and hopefully loved.