I think that developers do care about API stability (who wants to rewrite working code for no good reason?), but the effects of this time wasting are only felt

I think that developers do care about API stability (who wants to rewrite working code for no good reason?), but the effects of this time wasting are only felt indirectly by normal people. Since consumers have very little choice in their mobile OS, developers just have to put up with the thrash. It is possible to build new OS capabilities whilst maintaining a good deal of stability for existing APIs.