This is the part of PR that I fail to grasp. At a certain point, couldn't you just post "fuck you" on twitter and disregard the noisy mess? Would 100% of everyones' customer base actually walk away from them if they don't play "the game" on social media just right?
You might want to engage with 3rd party developers, but it's clear that it would quickly become much more work than supporting in-house clients. When the server team unintentionally breaks an in-house client, they don't start a big distracting PR war about it; and when an in-house client unintentionally breaks the server, there's leverage to fix the client (or the server) and insight into how the fixed client deployment is going.
It can also be difficult to fix sensitive or just complex issues in a coordinated way when there's unequal access as happens with in-house and 3rd party development. Being non-transparent is easier; although certainly less desirable to many.
If you have a compelling product, people often don't follow through on their plans to drop it.