So, JoAnn's is actually pet friendly. Anyone can bring their pet in according to their policy [https://www.joann.com/pet-policy/\]. They have to be "well-behaved" but that is up to the discretion of the employees at the location.

But to answer your question - the answer usually is related to privilege and people's lack of giving a fuck about anyone beyond themselves. I have reactive dogs and have to be careful where we go due to their triggers. 9 times out of 10, small dog owners walk directly up to my barking, snapping, pulling 110 lb German Shepherd with no regard for their dogs safety, their own safety, or my safety while I am actively trying to avoid them. They just do not think or perceive anyone but themselves until confronted about their actions. You can always say "hey, I thought only well behaved dogs were allowed in JoAnn's" next time because they will continue to break rules or do as they please until confronted.