I agree. I fundamentally disagree with the premise that cards should have "healthy" use rates, which they have previously defined as "in the same general magnitude as the use rates of other cards." If all cards cost the same elixir and there were substitutes then this would make sense but the whole point is that most cards are relatively unique and don't have perfect substitutes. Then use rates should always vary as various metas gel around the state of the cards. Then use rates would not be even. But as a meta gels, an anti-meta forms and use rates naturally shift again. It seems very unlikely to me that in a stable game we would have both uniform use rates and a stable meta.
If anything, frequent changes cause a subset of players to focus on one or two decks that seem safe even if not optimal in several kinds of metas, which makes use rate statistics an artifact of balance changes rather than a meaningful statistic. Then trying to balance around this artifact leads to wildly OP cards.