Yeah it's been brought up on the reddit, I think zarya is already rediculously powerful right now, so even if she stays the same I wouldn't mind.
The zarya energy grenade is just part of the learning curve, the beam is pretty crap against genji/tracer since their models are so thin and it's hard to keep the beam on them, but the grenade requires perfect leading and prediction of their movements. At my current skill level I still feel like the Mei Ice-cicle is easier to land, but no doubt after mastering the energy grenade it's strong in it's own right.
I've been playing a lot of zarya recently, with one conundrum. Reinhardt really messes up zarya in the usual matchup, he won't wreck your face but he'll make it difficult for you to do anything, and he can almost single-handedly negate your ult by just keeping his shield up while in the gravity well. Even if you kill his shield health on your own there's no garuntee you'll get a good black hole going, you might just get reinhardt. Cause once he lets down the shield its going to start recharging, so that's a short window to pop the black hole.
This, and reinhardt is a very popular character in public matches. Skilled or not, whether his team uses him to his fullest or not, reinhardt will pop up a lot. If I'm playing zarya, and I'm the only tank on my team, I can't just go swap to junkrat to get the shield down, and can't depend on a junkrat being on my team, or a junkrat that is on my team doing his job right. So I usually have to swap to roadhog, or just suck it up and deal with the huge annoyance all match.
The popularity of reinhardt as a "my team needs a tank, uuuuuh, oh there's that shield guy", and the popularity of "I only play genji, give me my play of the game I pressed Q and left clicked a bunch", and the popularity of tracer "lol I just did ult levels of damage with my pistols all over half your teams face, and you have no healer anymore", might go a long way to explaining the relatively low play-rate that zarya gets in public matches (at least near my MMR), all these characters work against her.
I guess the actual heart of this post, is a person playing tank and complaining that their team needs to be able to deal with and respond to threats. Cause the job of the tank isn't to rack up kills, it's to sit on the goddamn objective, stare into the face of the enemy, death itself, and yell russian slurs.