The rework led to many players uninstalling the game including me. It may not have seemed like a large hit at the time but it was. The player drop was undermined because of 3 reasons.
We didn’t all pack up and leave simultaneously. We slowly drifted away individually.
New players were still buying the game for the first time and were possibly pulled in by the controversy.
Many of us hoped that Blizzard were going to realize their mistake and revert her. Similar to how Valve reverted steam after trying to introduce paid mods.
Some people might have never even played during 1.0 Mercy. I believe a lot of players who enjoy the new Mercy do so because they have nothing to compare it to. Either they bought the game after Season 5 or bought it before but didn’t have substantial hours on her prior. She was really something. One of the lowest winrates in the game but highest pickrates. Super satisfying, fluid and epic. “Heroes never die!”
Reverting Mercy would not only pull in a boatload of players but also make so many people happy! Less toxicity, less darkness in these forums and proof that the developers care about their community.