How come the report system is so flawed?

I recently played a game on a different account and had lagged out, which is rare for me because I have fairly fast internet (50mbsp down - 10mbps up). Anyways I had lagged out and then came back about 10 minute later to have my team put in all chat that I rage quit within the first 30 seconds and that I was talking shit to my team mates and that I was standing around in base the whole time.

Once I got in the game I farmed for a few minutes and then immediately got a double kill, the game was won so there should't have been a reason for them to be mad.

After the match I got ban for an hour, I was literally ban for an hour because of what people said, no justification in it, just some low self esteem players that got mad because I lagged out so they reported me. Kind of ridiculous if you ask me.

            Side note - I'm a rather nice person in game, I try to encourage other to do the same, so behavior wasn't the issue.