In my personal case, I probably wouldn’t be worth much to SE or any other game developer since I don’t have the technical skills to program games, and that’s an absolute pre-requisite to be a game designer (as far as I know). I'm a geek fond of technology and science but I don't think that makes me a coder.

My skills are more along the lines of writing, communication and management. Maybe as producer or something that would work, but then again without prior experience and no technical knowledge? I doubt many would be interested, I also don’t know if I’d actually be able to pull it off. I do a bit of amateur game critique in my spare time though, and maybe that’s where I’d be the most useful to this industry, should I make it a job. But let’s not digress, that was just to answer your question.
What we do on forums is theoretical, imaginary design. Reality is a bit more complex than that. What we can do, as players, is voice our appreciation of various mechanics (feedback), and provide insights from one game to another. Sort of pollination, so to speak

But it doesn’t mean much more than that. And you’re right, arguing is pointless. It’s just an emotional need, I guess, to reply when something just doesn’t seem right.