Ok to eat off the cafeteria tray?

I know, I know, it seems bad, but hear me out - what we’ve got here is a whole 'nother surface, it’s put in the washer just like anything else - so why not use it? I mean, it does give the friendly cafeteria people less stuff to wash. So, what I want to know is - is there some hygenic benefit to using plates, or are we all just taken up by the evil utensil conspiracy?