This analogy seems pretty thin since Android's ecosystem is equally at risk here. This isn't going to scare these devs to another platform, it's going to scare them into not using the API.
Do you mean to say that they're just going to eschew in-app purchases? The Apple developer agreement, unless I'm mistaken, requires you use their API for in-app purchases or not have in-app purchases at all.
This analogy seems pretty thin since Android's ecosystem is equally at risk here. This isn't going to scare these devs to another platform, it's going to scare them into not using the API.