In terms of UI functionality "operational" and "good enough" are never sufficient. If you're not taking active advantage of the control mechanics that a platform can offer, you are not optimizing your UI and experience for the consumers that use it on that platform.
I'll give you guys one of the (sadly) more common examples.
You're on a PC game, you boot the game up, and the first thing you're presented with is a title screen that states:
"Press [ENTER] to continue"
First, this is the equivalent of a splash page on a website. It does nothing more than slow you down to getting into the product. But secondly, and most importantly, the game simply will not accept anything BUT pressing the Enter key. No Spacebar, no other keys, no mouse clicks. This requires the average PC gamer to take their hands out of resting position, visually acquire the Enter button and press it. It's basically when a developer assumes that the ease of sliding a thumb over to press the "start" button on a controller gamepad should transpose just as easily over to PC by making the player press on a button that isn't adjacent to a resting position.
These are small enhancements to the UI, but that doesn't make them any less important. If you're going to make a product, you make it the best product it can be (within budget and time constraints). And, true enough, this means a couple core changes between the PC and console platform UIs.