It was probably a good idea not to install only 2 winter tires on a vehicle that didn't have any.
However, if a vehicle already has 2 winter tires, it's unreasonable to refuse to install 2 more - that would be less safe, not more safe.
In the recent case, it sounds like a good call.
In the case previously re-quoted from another site, though, there was no reason to refuse. Sorry, your opinion is wrong on that one.
And, why is somebody buying snow tires in late July?