answered:
The same reason you don’t just randomly take a coyote or a wolf out of the woods when you want a puppy
domesticated animals are NOT the same as wild animals
Seriously people, when did you last see a wild, non-domesticated black and white hood rat in the sewers? How are the wild hairless rex rats doing in your dumpsters? Those brightly sand coloured rats doing fine not getting eaten out there?
Come on people! There are a difference between wild and domesticated animals! Wolves didn’t breed themselves into wild packs of chihuahuas hunting your sheep! Domesticated pet rats are NOTHING alike the wild ones out there.
Even rat lovers know not to go into the sewers and try pet some of the local wild life!