I'd like you to walk away from this understanding that the responses you're getting aren't because we're all hivemind "we must hate symmetra". If she had a couple tweaks she could be easily OP, and for a while was solidly in the meta. She's not there now, because she's not good. Her projectile is very slow, easy to dodge, and her turrets are super easy to kill. She charges Zarya to 100 so fast. She's also very easy to kill as long as you can aim, or if you have a hog on your team. Most people do. Her ult is also terrible. First, you have to die in order to use it. You're not in the action for 10 seconds, so it's not a res. You've missed all of the action. it's also easy to kill, and easy to find. You lose out on a lot of time you could be using on attacking a point with a much better hero (if you want to stand close to people and hit them hard use Reaper) and if you're defending she is better but you're still losing out on a mei/zen/mercy/ana/etc that you could have instead. There are always, always, always, better picks. You are hurting your team in comp with her because you not only put them 5v6 a lot of the game, but you've also pre-tilted them. Because you have to play a hero that everyone else but you can acknowledge is terrible, you've got the other 5 people on your team either irritated, or resigned to lose. If you would switch, everyone would be happier. Even you, because you'df likely win more.

But wait you'll say, there are high level sym's! I've seen them in streams! Yep, there are people that play sym sometimes in master level. They are able to do that one of two ways, 1) they also play another useful character at a high level. AGpoison is a good example of this. They will play sym as long as they can until they know they have to switch to mcree in order to keep their level up, and they have a 60% win mcree. Another way you can is 2) teaming up with a top100 and hoping they keep you up. SteveO was doing this just yesterday. I've never looked at his profile, but he likely also plays another high level hero to keep himself up ion the ranks as well.

You are putting your team in a disadvantage in a number of ways with a sym. You make a post about how everyone should just play as a team, and right off the bat by picking sym you subvert that argument because you care more about playing that character than getting your team a victory. What hurts people in low levels is that they tilt easily, don't communicate, or just have a mechanical deficiency they are working on. When you play sym you make the first two items in that list worse.

This is not some sort of arbitrary fashionable meta list that we're all just trying to follow to look like the pros. I am all for people playing bastion more and figuring out a strat, because he has shown in many instances to be something that can work. Play phara. Play torb. Play mercy. There are better options to use than any of those heroes, BUT they have use and are still good enough to support themselves and earn a spot. Sym doesn't so that. She has no redeeming monster Ult. She doesn't provide a boatload of health, and she doesn't heal your teammates and keep them in the fight longer. There is nothing she does that numerous other heroes don't do better, there are some like torb that are almost exact copies and every aspect of that hero is better.

You are failing to understand why heroes are picked, how to judge what makes a hero good and bad, and how you effect your team dynamic with your actions.