You keep mentioning profit as your main argument. You said several times that it would be more profit to let new people buy them.
I don’t think you are taking into account the fact that the limited availability actually makes a lot of money. As you said the limitation is artificial and they could just make more but the scarcity makes people less reserved about spending money.
The next time a limited skin comes around, as somebody who is upset about missing out, what are you going to do? You will probably bust out your wallet and snag that exclusive stuff because you don’t want to miss out again.
Now say they announce that it will be coming back every year. Maybe you don’t feel such an urgency to buy? Maybe you say “Well if I really want it I can always pick it up next year.” And potentially do not buy it.
The artificial scarcity makes people more willing to shell out money which = profit.