The problem with Hearthstone is that it is too consistent. You always have your mana when you need it. As such, that five-drop of yours is coming down on turn five. In Magic, your five-drop may come down on turn five in one game, and then have to wait until turn seven on the next. Mana is too consistent in Hearthstone, so every game feels the same. On top of that, card draws are more consistent because you have 30 cards as opposed to 60 in Magic/Pokémon and 40 in Yugioh. And because you don't have to put lands in your deck (or mana crystals, whatever), you can cram more good spells into your deck, so your odds of getting a "good card" go up. Finally, the mulligan process in Hearthstone of being able to pick-and-choose makes opening hands more consistent, especially since there's no penalty for taking a mulligan (either in full or in part).It makes the point that the randomness in Hearthstone is just surface randomness built into a few cards. While the deeper deck construction is far more consistent in Hearthstone than in Magic.
Note too that this player thinks consistency at this level is a flaw in the game, not a positive. I've commented before on how the initial hand in card games (and subsequent draws) is a far more acceptable source of randomness to players than other sources.