For me, Mercy has always been fun. Her kit has been amazing, even it was strangely shifted. Her character, mobility, and role all spoke to me from the beginning to now. I still keep playing her for those reasons.
However
Mercy has become less impactful and less engaging the more nerfs she received.
The rework lowered her skill ceiling, which meant that your character now peaks far lower and her potential is far less in competitive scene. The devs intentions were to make her more engaging by making her do the exact same thing she already does before her ultimate, only in ultimate it’s easier and you can go upwards.
Regardless of that, she was still engaging enough to play until her healing rate was absolutely toned down to these levels.
She is a hero of her class that can’t do her job properly. If Mercy could put out her healing and do damage at the same time, then the healing strenght wouldn’t be an issue.
You can’t engage in a fight nowadays, because either your healing can’t keep anyone alive, and you don’t have a dps option to harm the enemy while you’re healing.
If a mercy whips out her gun, she is almost immediately scoffed to go back to healing and stop doing damage, that’s because her main role is to heal. Yet you can’t even do that properly anylonger.
You have no role in you team, and it only feels frustrating to play a hero you love that cant do what they were designed to do.
Much like if reaper was now nerfed in damage enough so he couldn’t properly take down tanks, or Tracer having 10 second cooldown on her blinks. Defeats the purpose of the hero.
Bottom line is, I think for many MMains, is that they want their hero to do -something- properly.
Either let her healing role be good enough to sustain, or lower it more and give her the ability to do damage as well, like the other supports do. When she does none of those things properly, it makes people frustrated. Power has been taken away from the player and all anyone says to the complaints are
“Just pick another hero”
Of course it’s just my opinion here, as OP asked. But I do think it’s just the frustration over the hero they love to play being pulled down so far when there were other options to create the balance. No one wants mercy to be op like she used to, even mercy mains protested against it then.
And then the comments of plenty come in about how you should simply adapt to it, by the same people who refuse to adapt to counter brigitte.