Well, why do you think that is? As far as I can tell it's some combination of protecting users and protecting app store revenue, both of which apply equally well to macOS as iOS. The only difference is that the Mac app store isn't as established so they can't force everything to go through it today.

That said, I don't know how it could be tired, as these laptops were just released. I also don't know what you mean by 'un-nuanced', but I don't see how understanding why they favor lock in is relevant. He's not talking about the merits of a closed ecosystem or locking things down, just about whether or not they might lock things down further in the future.

I think most people understand the motivation behind Apple trying to control every aspect of their products, whether or not they think it's a good practice.