Excesive RNG is the crutch of lazy designers. I know, I know! The skins and the taunts don’t affect your game, but completionists will go bonkers about the RNG. And reasonable players will just stop bothering after a while, much sooner than if you had given them actual goals upfront instead of “You MIGHT or MIGHT NOT get this.” They don’t even tell us the percentage!
I would feel better about the skins if the ones you can unlock just by playing the character weren’t subpar. Just recolors, and not even -good- recolors. There’s just too little contrast (except for the second skin, which works just fine).
Unlocking stuff should feel gratifying. Players should be happy that they are spending their currency. Not frustrated and not alleviated when they finally, FINALLY get something they actually wanted.