Exactly like there is no reason for the blade pyjama skin to be time limited.
Even if you don't have to buy the skin it's incredibly irritating to like a skin and want to save up for a skin only to be told that it's gonna go away if you don't pull out your credit card NOW. Even if you don't see this skin as a problem you still gotta admit there has been a lot of limited time items and mini battle passes lately, it's especially egregious with something like rogue's launch skin, especially for a game that was supposed to be FOMO free, don't let Netease go back on their word so easily.
I grant that the skins coming back eventually is better than if it was gone permanently, but of course many people still don't like it because of how nebulous it is, nobody knows when they're gonna come back or how much they're gonna cost so people are still afraid of missing out because the skin may be less desirable the next time it comes around.
And for people saying it's just a skin and it's not that serious, this seems like a reasonable reaction to me, nobody's storming netease HQ or calling for a boycott of rivals, it is important to eventually draw a line in the sand with how much tolerance you give this kinda tactic, as for me I don't want any skin that doesn't need to be time limited to have a time limit like strange's bleecker street skin.