That feature was originally meant to be an image sharing platform, but had an unfortunate name and the button being called “Save” (although it did have a cloud icon on it) didn’t help either. Long story short, people mistook it for a screenshotting tool.
It was definitely a blunder, don’t get me wrong, but it was dumb rather than malicious.
Tbf, when Mozilla realized their blunder they cut out the sharing part and left it just as a screenshot tool because that’s the part that people liked.