The saddest thing is how uncritical they try to be of Apple in these kind of posts. It's pretty clear that they fear retribution if they are seen as publicly complaining - which, along with the same approach to journalists, tells you a lot about Apple's attitude and culture. I wish Apple would see that in the long term, insulating themselves from criticism is not in their own interests.
If things are really bad enough, why not create a federation of developers to build developer clout and threaten Apple with counter action based on Apple's action?
Apple is a single focus of power. Developers are numberless and spread all over the world. Your suggestion to try to combat that situation by concentrating, essentially "unionizing", developers, would fail for two reasons.
One, the developers are so numerous, diverse, and independent of one another that there would be an endless supply of developers willing to "cross union picket lines" and make more money with the competition reduced. In a sense, it's like a mine with a hundred times as many miners as it needs, most of whom are struggling to get more than an hour a month of paid work and would do anything to get more. Also, the most important "miners", Apple itself, Google and Facebook, have their own agendas and wouldn't care about any "developers' union", and if you combine the apps Apple, Google, and Facebook contribute to the iOS platform, the vast majority of the rest of the devs could disappear with almost no impact on Apple other than that Apple would stop announcing the number of apps in the app store during keynotes. They'll eventually stop that anyway.
Two, Apple makes very little of its money from app sales. The indie devs aren't the real miners. The miners are the actual employees of Apple and Foxconn. Apple sells hardware, and as long as they have their own apps, and apps from Google, Facebook, a couple of big game makers who are getting rich on iOS and aren't going to walk away from it, plus apps from a small percentage of the indie devs, consumers will keep buying Apple hardware. Again, the vast majority of iOS devs could "walk off the job" and the "mine" would keep operating as if nothing had happened, other than a bit of editing to the semi-annual PR message.
An "iOS developers' union" would have so little leverage over Apple that Apple probably wouldn't even "fire" developers who joined it (revoke their dev credentials). It could simply ignore them and go on with its business.
I think if iOS developers were able to brand and band themselves together and build clout with consumers they could make an effect on certain policies. If they notify consumers that they want to provide the services that customers want, and Apple is the one getting in the way, they can begin to influence.
Are you of the opinion that there's no amount of developers or very popular apps that wouldn't make Apple reconsider policies? I believe this is a though in an oppressed paradigm. How else (other than potential legal action) Apple's decision to start allowing bitcoin wallets (arguably a direct competitor to Apple Pay) into the app store.
Whatever you think of the App Store's policy, users have freedom of choice in which mobile platform(s) they buy, and developers have freedom of choice in which mobile platform(s) they develop for.
Apple has made no secret of their desire to strictly control their platform. To prevent them from exercising control over their platform just because users continue to choose iOS devices and developers continue to dev for iOS devices is absurd.
We just had a post about whether or not open sourcing a repository conferred some responsibility on the releaser to maintain it and offer support. The situations are not dissimilar: putting into public a thing which becomes popular does not convey to the public control over how you shape your creation.
There is not much choice, either the closed Apple ecosystem or the open Google ecosystem which aggregates your data. Everything else is unpopular. Personally I use a Jolla phone but this doesn't help an app developer who needs to make money for rent and bread.
