The opinion of pro players >>>>>>>>>>>>>> than some guy on the official forums who just made his 30th "Winston buff" thread
I constantly think "why doesn't Blizzard just try what this pro player said?" or "why not encourage them to test PTR specifically and take their feedback as priority" assuming they're gonna actually use the PTR to balance things instead of just a beta test for upcoming changes or like the D.Va/76 patch.
What matters is if the arguments are reasoned and backed by both maths and practices. "Feelings" do matter too but not nearly as much since those aren't realistically quantifiable outside extreme examples usually correlating to player use (if a character really does suck and is no fun it usually does end up getting played or winning a lot less even among casuals who won't even know about a tournament, much less watch it to mimic).
You don't need to be a pro player to have the math and argument be on your side, and it's far easier for a reasoned augment with math to get lost among the "buff my main and nerf the toons I just lost to" topics when you are an unknown nobody on a message board and pros have that additional platform/fanbase to echo whatever they are saying.
I don't think it's impossible to make a character good for both, but after playing WoW for many, many years and how that game was balanced for PvE and PvP and all the various raid tiers and whatnot (some of which I am still salty about to this day), it's really a coin toss on whether or not they will listen to the lower rungs of players even when they should, and it can get very frustrating when it's clear high level team play is the main consideration for a buff or nerf to the point where it feels like other modes didn't actually get acknowledged. I'm not gonna act like it's not a lot of work to do so, but that doesn't mean they shouldn't keep trying.
In reality though, most of the characters feel playable to me and my admittedly short time with the game. Some do seem clearly better than others at certain things that seem to be more valued by the playerbase that I find questionable in PUGs, usually from those people trying to mimic the last tournament they saw, but that's no different than something like LoL so I'm used to that as well. It helps to know that some of the more questionable choices right now (Ana and D. Va and 76? I think) are up for a look soon.