I've been debating whether to eventually get this game, but it seems like this system is very similar to roguelikes with tidbits of "metagaming", like Spelunky and Desktop Dungeons. Roguelikes are meant to kill you, and to be hard, sometimes impossible. What you *can* usually do, as you learn the game, is to mitigate risk.
For instance, in Spelunky you get to unlock the different areas the more you play. Every run allows you to drop money into tunnelling directly towards the next area, but before you get there you're going to have to "grind" the first area quite a bit.
Desktop Dungeons only allows you to play certain classes or new dungeons after you've completed challenges. There's a definite metagame progression going on.
Stealth Bastard Deluxe is another game, not quite as roguelike-ish, that gives you advantages after you grind levels to perfection, and you go back to the early levels and try them again with advantages.
All of these games received pretty wide critical acclaim, which makes this difficulty, dying and retrying, getting little metagame bonuses each time you retry, a perfectly legitimate game mechanic. The complaint you have against Rogue Legacy can easily be applied to any of the above games.
What might happen, however, is that the gameplay itself is not enjoyable to you, in which case it's not a fault with the metagame stuff: it's just that the gameplay itself is boring to you. We "grind" Spelunky and Desktop Dungeons because the gameplay itself is interesting, i.e. the grinding itself is enjoyable. The metagaming simply adds to the enjoyment, as we get a further feeling of accomplishment. If you don't like the gameplay, no amount of metastuff is going to work for you.
So, is the gameplay boring? Not enough enemies, not enough variety, the platforming doesn't feel good? What is it? If I remember correctly, Spelunky only had a handful of enemies types, for instance.