This seems a bit harsh. What about an elderly/ill/disabled person, who would love the companionship and would make for a kind and responsible owner, except that they aren't capable of consistently giving the dog sufficient exercise?
I think many dog breeds would outsmart the robot after a while.
I certainly can't imagine trusting a robot with a dog any time soon. Maybe there's a semi-autonomous, supervised use case, e.g. human takes dog & robot to a park; robot walks laps with the dog, staying close enough for the human to see what's going on and intervene if necessary. The set of people that would help (i.e. for whom it would be both needed and feasible) might be pretty small, though.