I see here a vague argument focusing on one kind of rant post (US pilots were *always* better, Soviets 'didn't care') on one hand and bit of a tendency to Soviet fanboy-ishness on the other, with all due respect.
To sharpen the points, one of them is whether Soviet and US fighter unit quality, all human factors not just 'pilot's skill', tended to be equal in WWII era. The Korea example seems to pretty strongly refute that as a basic assumption: two sides met head to head in broadly comparable planes, with tactical factors generally favoring the Soviets, in a large sample of combats, and the outcome was quite lopsidely (by standards of kill ratio's verified by each side's losses) in the USAF's favor. Well 'I don't know' and quibbling about Soviet operational losses, when we know their combat losses directly from them, seem to have been the only counterarguments offered to that example.
However that doesn't prove that all US fighter units were better than all Soviet throughout the era. For example see books like "Fighters Over Tunisia". Experienced LW fighter units manhandled green USAAF ones in that period; though they still generally apparently also held a serious kill ratio advantage over the already 2 years experienced Soviets at the same time. The USAAF wasn't clearly better though, not at that point.
Still, the 'final product' so to speak of WWII era doesn't appear to have been too close to equal, and F4U-4 v Yak-9U which implies very late war fighter units, where both sides had digested WWII combat experience, closer to the Korea example. I'd still expect the F4U-4 units to score several:1, mainly on the same basis F-86 units did so, not because their plane was so much better.
On who lost more planes in WWII I don't get that point, the Soviets lost more. I don't see how it proves or disproves though who 'cared' more. Which isn't really relevant to how F4U-4 and Yak-9U units would have fared against one another anyway. But is anyone really suggesting the Soviet political and social system cared as much about personnel casualties as Western? That seems a clearly absurd statement if so. OTOH every country faced the reality that you have to get some of your people killed to win a war, to some degree.
Joe