If files weren't completely deleted when the trash was emptied, then people would be kvetching about the horrible security implications and the only way to be sure was to keep files on the local disk so that when you emptied the trash, the files would be really gone....
I think the arguments can be dumb too, but the guy actually lost files here. And it's the kind of mistake I could see myself making pretty easily. In other contexts you protect against this with non-local backups (ironically, that's probably 90% of my usage of Drive), but there's no equivalent in the cloud world. It's a real issue that needs to be addressed, I think.