Absolutely there is. I know you've been on a kick lately about "only the roleplay matters" and "people worry too much about the combat minigame" but for a lot of us, the mechanics of how the game plays matters a lot.
If I didn't like the mechanical aspect of the game, I'd just play Dungeon World instead.
Fair enough... using mechanics that are fun and interesting indeed do make the game part of D&D more enjoyable to play. If the dice-rolling kinda sucks, then using the dice rolling is a hassle or an out-and-out failure.
But I still do question though whether
specific mechanics actually feel like what they're meant to represent? Or is it just that our coloring of said mechanic with a name thereby gives it said "feel" in our heads? Like if you were to remove the identifier from the mechanic, would any of us be able to tell what the mechanic actually "feels" like it is doing?
Case in point, there are what... dozens of different features that give advantage on a roll? None of us can say that advantage "feels" like any of them. It's only when we layer on top of it the roleplaying identifier (or fluff) of "This advantage comes from the person getting lit up like a Christmas Tree due to this Faerie Fire spell that was cast on it" that we in our minds associate the feel of the Faerie Fire spell to the mechanic of advantage. Or like I said above... does rolling an extra +2d6 damage "feel" specifically like getting in a really good shot in under the target's chin or around it's armor in a manner the target didn't see coming... as opposed to say rolling an extra +2d6 damage due to calling down the power of your divine oath to smite the unbeliever? (And yes, I realize DS is +2d8 not 2d6 but the point's the same.) It's only because we call one set of bonus damage "Sneak Attack" that the mechanic acquires the "feel" of getting in a really good shot in under the target's chin. But without
saying "this is a Sneak Attack", the mechanic wouldn't "feel" like anything specific other than bonus damage.
And that's really my point of the Psi Die-- it doesn't "feel" like psionics because no one has actually used it yet. We haven't associated the mechanic to the name in our minds yet. But I would bet that once people started actually playing with the mechanic and having a character that used the mechanic... eventually the mechanic
would come to "feel" like psionics because you'd be identifying it as such. Just like adding a +2 to damage and resisting BPS damage "feels" like going into a murderous thundering rage.
But hey... that's just my opinion. I could be wrong.
(EDIT: Now if you want to say that the Psi Die just doesn't feel like a fun dice mechanic to actually play in of itself... then that's a whole different story, and I can understand someone's distaste for it and my point above doesn't apply.)