There’s a problem common to democratic (small d, not referring to the American political party) systems where the proper units for measuring effect are discarded, and replaced by the unit of voters.
It should be pretty clear that nerfing a deck that’s considered “unfun” will yield only mild happiness, if any at all, to its supporters. It’s not like you play against the same deck every match; on the high end of things we’re talking about 1 in 4 games. In contrast, it should be pretty clear that having your deck nerfed to the point you can’t play it anymore is pretty devastating if you loved the deck for what it was. (If you were only playing it because it had a disproportionate winrate, it’s easy to move on with a Dust refund.)
So if each of those ten cheers got +10 happiness, and each of the five jeers is -25 happiness, you’re not increasing the net happiness of the system. Indeed, if you do this twenty times to twenty different decks, you would see almost everyone’s net happiness decrease. But each instance of such a proposal is going to be popular because the majority will look at the situation with shortsighted selfishness.
It’s worth noting that the design affordances of social media are inherently democratic. On Reddit you don’t get more votes than someone else if the impact of a proposal would disproportionately effect you. One person, one vote. These affordances in turn apply conditioning, like Pavlov’s dogs salivating at the bell, making one want to say popular, or even populist, things. Social media brainwashes people into thinking in terms of units of democratic popularity and not in terms of units of real utilitarian impact. Argue against the nerf, and you’ll get 5 cheers and 8 jeers, even if you’re a persuasion god and you convince two of them you might not be wrong.
You don’t control what your opponent plays, but you do control what you play. I stand by firmly by the conviction that giving players the choice to choose what they play as thoroughly outweighs the frustrations caused by what they play against, and that when cards are nerfed because they’re “unhealthy” it invariably is the case that that card existing created more fun for its lovers than it created unfun for its haters. So, no, it’s a lie that there are cards wholly unhealthy to the game and the overall meta, except when those cards win too much.
I’m not against nerfing cards due to too high of a winrate. This is a problem because the player playing as that deck might not love the deck for what it is, but just for its disproportionate winrate.