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.
And And those who lost their file will blame the UI.
I understand the frustration and how terrible the poster feels but this anecdotal argument is irrelevant to the actual safety or UI quality of Google Drive.
There will always be users who lose their data due to glitches, technical illiteracy, bad design etc. There are literally dozens, maybe hundreds of million Google Drive users.
The lesson that can be learned here is this:
Your personal data management system should never have a single point of failure.
Disclaimer: I was a Googler sometime ago but wasn't anywhere near the Drive team.