But the fact is, that flat out isn't true. Machamp/Donphan can OHKO it. Reshiram can OHKO it. Magneboar can OHKO it. Sure, it has energy acceleration, but lacks the consistent draw needed to get said energy. It's just flat out inferior to everything else.
Machamp and Magnezone Prime can OHKO almost anything when they can deal 150 damage.
Minus the few popular cards right now, and the few cards that have it's weakness, not many cards can OHKO large legendaries like Zekrom and Reshiram. That is the whole point.
It's
easy to say that the best decks in the format right now can handle them, but that is
why they are the best decks in the format. The other cards that aren't being played aren't being played right now because they can't handle cards like Zekrom and Reshiram. It would be hard to argue that.
Compare Reshiram and Zekrom to Lugia EX. Lugia EX had 30 less HP, only one attack, a ridiculously costed attack (even if the holon pokemon made it much easier to power) to add to that, and double weakness. Your opponent got 2 prizes for knocking it out.
Reshiram and Zekrom only give one prize, have two attacks, one of which deals 120 for only one type of energy, and a rage attack to capitalize on any damage it takes since it's hard to OHKO for any card that isn't hiting it's weakness or dealing 150 damage.
Compared to Ho-oh Legend, it doesn't require needing two pieces to be put into play, can deal 20 more damage for 1 less energy, and can use it's first attack for any type of energy.
It's hard to argue that there isn't some form of "power creep" in these legendaries. That's the whole point. Not that there aren't any counters, just that the cards are at a higher level than a lot of the other pokemon.