Saying "the game has changed" since AHI does not refer to the plane set alone. There have been changes in the demographics of the player base and culture, changes in gameplay style, and possibly changes in gunnery modeling/flight modeling that will effect things. (Try getting a 1K kill now, even with a C-Hog. Not very easy)
I think gameplay, hordes and all, now favors a fighter that scores exceptionally well for out-and-out speed, OR is an exceptional turner. I disagree with your assessment, I *do* think the SpitXVI has had a tremendous effect on gameplay, its domination of most other planes in the "middle" of the speed continuum greatly blunts their effectiveness. The two most common aircraft in the arena are the P-51D and the SpitXVI. It makes sense to compare to these two first and foremostly when considering the feasibility of flying a given aircraft in the LW MA. But there is a significant difference between the two; Nearly everything slower than the P-51D can claim out-and-out superiority, or at least rough parity in maneuverability, and often enough superiority in thrust/weight, to say nothing a host of other factors where the P-51D also tends to be mediocre. The same cannot be said for the SpitXVI!
The C-Hog is at the upper end of this speed continuum, and not near enough the top of the maneuverability continuum to truly out-class the SpitXVI as a turn fighter either.
Also, did the C-Hog go unperked enough tours for its usage to "settle down?" I go to the DA frequently and C-Hogs simply do not seem to be 1 out of 5 fighters you run into.
As to the performance, you greatly undervalue firepower at the very least. Durability and being CV capable possibly as well.
On the contrary...I realize the value of firepower. I also realize that many planes in the MA pack a punch comparable to that of the C-Hog, while possessing enough inherent advantages over the C-Hog that one cannot truly say the C-Hog is clearly superior. The most telling comparison is the Typhoon...both are 4 cannon birds. The C-Hog's k/d stats are obviously much, much higher. Yet the Typhoon is clearly superior in low-level speed...a trait that for obvious reason greatly increases an aircraft's potential to maintain high k/d rates in the MA. The only reasonable conclusion for the C-Hogs much higher k/d rate is who it is being flown by and how it is being flown...and these are factors which might *come* from it
being a perk plane as much as they are reasons for it to be a perk plane!
In the end, the F4U-1C simply does not seem to enjoy the sort of performance advantage over the vast bulk of the plane set that the Me-262, Tempest, or even SpitXIV (to a much lesser degree) possess. It is in fact, not quite as good as it's stablemate the F4U-1A except for the Hispanos. Which leaves us with popularity...I find the notion of perking something that does not clearly give the player one, or better yet, many clear advantages over most of the planeset arbitrary and unfair, even if 75% of the people flew it. There is to my mind a difference between balancing the plane set through making the largest number of choices viable in the MA by perking those few planes who plainly outclass most of the rest vs. "forcing" variety when the players show a strong preference amongst equally viable choices.
There is a mitigating factor in the C-Hogs case though, it was a historically rare variant, and an aesthetic preference for keeping more common variants flying in the MA, and a similar preference for seeing something *besides* C-Hogs off of a CV, is more acceptable.