Congrats on your new boxer.
It's not just rescue and animal welfare people with the hard and fast "check lists". When we were looking for our first dog we called an English Cocker breeder but she would not sell us a pup because we didn't have a fenced yard, end of conversation. So we got a Border Collie instead. I suspect that if we were able to keep a Border Collie pup mentally and physically exercised and happy without a fenced yard we would have been able to do the same for an English Cocker.
It takes time and effort to get to know potential adopters or puppy buyers; it's much easier and faster to have a hard and fast checklist to cut down on the number of possible homes for those who are trying to deal with placing large numbers of dogs day in and day out.
