Too true. If I had a dollar for every crazy excuse people have to dismiss the fact that their dog is fat as a tick!
"He's just a BIG dog!"
"He loves to eat"
"He's SOLID, not like those skinny little __breed__ you usually see"
"He's SO much happier like this- I could never limit his food!"
"They're supposed to be stocky"
"He doesn't need to (ie: can't) walk, I'll carry him everywhere"
It's especially prevalent in dogs which were adopted/rescued in lean/thin condition- people want to fatten them up and tend to go way overboard.
Can't tell you how many times people have assumed that my lean (active, shiny, healthy) dogs were/are sick -or recently rescued from neglect- because they're "skinny". The poor things