I mean, it's fine that you feel this way, and you are probably correct - it wasn't designed for it. But I suspect for a lot of us , me included, it serves that exact purpose. I post so that strangers on the internet read it and give me likes. I compulsively check my comments section on my account to see how many upvotes my comments have. Every time I see my total Upvote count go up, I get excited and I rush to see who has agreed with me again. If it goes down I immediately get angry and defensive that someone is downvoting what I said. And surely, you participate in the same process, even if you don't feel as strongly about it - otherwise, why are you replying to strangers that you are unlikely to ever meet or speak to again?
It might not have been designed this way but it's exactly what it is. And clearly upvote/downvote system didn't happen by an accident, it's there for a reason.