I don't think the rating system is trash, at least once enough people vote to drown out the "strategic" voters. But it shouldn't be the only criteria for your decision about what to watch. If I see somehing that's below 7 that a fairly reliable indicator that it's terrible. But if it's 7.7, then that's ambiguous and I'll want to know more. MDL voters severely punish brevity - the Best Series Ever Written would get a 7 if it's six 30-minute episodes, and the same thing will get an 8.6 if it's stretched out to twelve draggy and repetetive 45-minute episodes. So a 7.7 for a shorter series to me is a good rating.
Then look at the comments. Some people give a series a "1" if there's any sex in it, or if there's any male aggression in it, etc., so it's important to see why people have issues. If the complaint are "it's really boring" or "nothing makes sense", then that's something to listen to.
Speaking of 2gether, it's interesting how its rating has sunk over time - it's fallen to 7.8 and it used to be much higher. Sometimes there's excitement over something when it comes out that doesn't hold up well, so the time since airing should also be a criterion in your evaluation.
Using 2gether as an example, I gave it a "9" at first because the first few eps were really good - it was refreshing to see two normal guys as leads, but after ep 6 it turned as formulaic as is achievable and became dreck. I forgot I'd given it a 9 until someone pointed it out later and I lowered it. But many viewers likely binged it long after it aired and so gave it a more realistic grade and so the overall rating sank.