I think this illustrates yet another distinction witin the term "player skill" that clouds the debate because different people mean different things.
In the above you seem to be defining player skill in terms of presentation. And I 100% agree with you that it should have no bearing on the outcome. It's the method/plan/approach itself that matters, not how well it is roleplayed. This mostly comes up in discussions about Charisma.
Because Charisma is so often abused by players dumpstatting (given the various methods other than "in order" rolling) that it's the most common case across game systems.
I've also had players who dumpstatted Int... and then try to use player knowledge to solve traps and such. I cut them off with the att check, just like I do the Cha dumpstats.
And I don't care how nimble the player is, if the dex is 7 on a 3-18, no one will be impressed by their dancing itself, tho' proficiency/skill might impress by them being barely competent at 30 different complex dances... which is impressive, but for different reasons...
Then there's "player skill" in terms of decisions: players choosing courses of action, or suggesting ideas to the group, that a low Intelligence character "wouldn't think of". In general I think that enforcing certain kinds of roleplaying on other players is dumb, but this one is just about the stupidest one there is. Not only would I not come back to a table that imposed this, but I would probably just get up and leave.
Knowing that, if you showed up at my table, ID'd yourself by handle, I'd say, "find another table," because I use atts & skills to gatekeep character action choices.
I use the game to provide the texture to player choice. If you chose a low IQ and low knowledge character, and are providing all the tactical plans, you're not playing the character as written.
Then again, I've had, off and on, mentally disabled players as part of my groups... and them being able to play other than basic fighters was enabled by, "Need help? Make a roll on ___, and on success, the others or I can give you suggestions"
I run my games as games first, story-generators second. Story constrained by rules and setting.