To be honest it seems like you're a bit offended that Valve is dropping a platform that isn't used by ~99% of Valve's x, so you're saying essentially the same thing but with a sour grapes twist. That's why you brought up iOS market share another comment with a smug sort of "gotcha" tone, despite iOS obviously not being relevant to Valve at all.

Listen, nobody is denying that MacOS and iOS are relevant platforms generally, but they aren't relevant to Valve and this discussion is about Valve. There's no reason for you to be upset about this.