Not sure why would you want them to leave under these circumstances. There is a big difference between not focusing (e.g. not developing new content), and actively pushing people out. The reason Planet Fitness did what they did was not because "gym rats" were not profitable by themselves, or because they didn't want to invest into more equipment and heavier lifting weights. For better or worse, they did that to appeal to people who are not fit so they wouldn't feel "intimidated". It worked well for PF, but it's a shitty approach to personal development if you ask me.
In a game where new chapters have been added regularly and new chapters are expected the "content" is the context of development. In other words, while actually developing new content is, as you say , different, not meeting peoples expectations is an active way to discourage them. Planet Fitness may have been more aggressive in their actions but in a game where one waits for what is, in essence, promised (that we have the expectations implies a promise based upon past performance), not fulfilling the promise is an active way to discourage (i.e. push) people out. You may be right that Planet Fitness is much more aggressive at it, and I'm not saying Inno has any plans to do it, but if it did one way to actively discourage long term players is to stop creating new content.
I'm not the one who would want them to leave, but if owned Inno and I'd always ask myself at what point will the road to "success" (finishing the last chapter) be so long that most players quit before reaching it? At some point people have a burn out level, even in this game. If the burn out level for 99.99 percent of players is 25 chapters (7 years, let's say) and the cost of the 26th chapter is X, you can only justify the creation of that chapter if it brings in the revenues to pay for it. So let's say only 1000 players will ever access the 26th chapter and of those 1000 players only 100 are regular payers. The cost of having the chapter then exceeds the revenues generated by having it and thus, if you can find a way to reduce the number of players at that level you no longer have to consider their desire for the 26th chapter and/or their complaints about when it will be added. Nobody is currently complaining about the delay of chapter 18 because 17 comes first. In the same way if nobody gets to the mythical chapter 26 (or reaches the end of 25) then you don't have to have chapter 26 and thus the cost of developing chapter 26. It's all dependent upon measuring the need and if you can reduce the need for the chapter by removing (i.e. discouraging) players at the high end from needing it (no one who is not playing needs it, right?), then it's a winning combination.
In addition, if the game gets to chapter 25 and that becomes known to be the last chapter those who are in chapter 23, 24 or so will "push" on to say they "finished" the tech tree (which may be a badge of honor among some). I was once in a city building game in which having 1024 cities was the max you could have. I still remember the day I finally reached that magic number. It's not everybody's cup of tea but "finishing" is mine. What I'm saying is that knowing where the end "really" is may motivate a few to press on to get there whereas knowing more and more chapters will just keep coming may actually cause some people to leave.
It is a good way to stay connected in one more small way. We also have a bunch of newer players who I'm hopefully helping learn the game and grow. It is going well and I am starting to enjoying the game again instead of the drudgery of keeping up with other people's expectations.
BUT, it really stunk having a sale on expansions while knowing a FA is on the way. (More space needed) I flatly said no to our kids who I buy diamonds for and I had to advise others that it may not be wise to buy premium expansions since they will soon make the tournament more difficult and already do make the Spire more difficult. I have spent $$ on this game for years but at this point I have a hard time encouraging anybody to spend, like for room to add AW's, when it is becoming spending real $$ to make the game harder. Guessing Inno thinks that will semi-force more diamond spending. I'm retired from Accounting and there is just no way I can make that add up
One of the things that you constantly notice is reference to how it used to be....usually better than it is now. New players, of course, don't have to contend with that as they enter the game as it is now, and thus the difficulty of the Spire, etc.... will not seem to them anything more than "how it used to be" in a few years. If you had come upon the game when you started as it is now, would you feel the same way about spending $$? Maybe you would, maybe not. But one thing is probable, if you reflect many long term players the revenues from those long term players will be dropping -- which means at some point there won't be enough players from the pool to justify making another chapter for the long term players who have reached the end of the line.
And, of course, changing your "role" in the game may, as you discovered and remind us, change your attitude about playing the game too. I was pleased to see you comment about that since I too like taking small to mid level players and helping them grow. That too is part of the game.
AJ