In the abstract, what would best serve developer interests is if platforms are as compatible as possible, especially in their superficial details. That minimizes switching costs, both in terms of what it takes to port real software from one platform to another, and in terms of what a developer must learn to apply what they already know when working with a new platform.

Taken to an ad absurdum conclusion, developers want all platform vendors to coordinate in order to minimize switching costs. Of course there are lots of good reasons such a level of coordination will never be realized. :)

In the meantime, there will always be efforts to create adapters which generalize the interfaces of multiple platforms and put them behind a common wrapper interface. But while such interoperability efforts serve developer interests, they work against the interest of vendors in encouraging platform lock-in.

The dynamic isn't pure in terms of real product offerings because vendors also understand that portability provides value to developers, and so some vendors will provide at least some portability in order to differentiate themselves. But I maintain that the fundamental interest structure is unchanging.