I think there's a very clear disconnect between players who want a power fantasy, versus players who want a challenging strategy game.

I notice a lot of players fall into the trap of only building for the deck itself, trying to force the kinds of hyperoptimized archetype decks you would see in a constructed TCG. The game allows for a lot of flashy combos that can feel like an unstoppable force, but if their deck only ever does one thing they will encounter some enemy that feels like an immovable object because it counters that one thing.

But then rather than accounting for that enemy's existence and diversifying their deck to be able to handle it, they rush to the Steam forums to complain that the enemy was unfair. Because the deck was good, it had this cool combo in it, and that combo beat everything else up until this point, so clearly this good deck shouldn't have lost!

It's like building a team of all Fire-type Pokemon that only know Fire-type moves, and wondering why you can't beat the Water gym.