100% agree! I think in the end if that's the way that work out for the company, then it makes sense for them. Especially for Motion, since there are tons of app in the market the follow the same strategy (fun fact, I also do the same thing for my own app that I developed 🙈 - I know it's bad but it generates a better profit compared to the other way around)

For Sketch, I think it's more about navigating users to the right path. If they know the #1 goal is for user to download their Mac app, then I would argue they should probably navigate users better (there are 6 buttons there for users to click), and explain why the Mac app is needed.

But as you mentioned, maybe they have launched some experimentations on this and found that this is the best way to go :p