I suppose I understand some of the frustration with folks that just bought their apex on sale, but doing a clearance to clear out old stock prior to releasing a new model is pretty standard business practice. There's nothing nefarious about it, and you got a good value on a proven product.
I think we also need to reframe what some folks are referring to when they say "backwards compatibility." What you are actually referring to here is "forward compatibility" in that you want the old apex brain to be compatible with the new energy bar. While that would be fantastic, it's a truly unrealistic expectation.
Your dirty old DVD player can't play Blu Rays. Your PlayStation 3 can't play PlayStation 4 games. This is just how innovation in technology works.
There is absolutely no evidence that Neptune is pushing us out of our old systems. In fact, per their FAQ, we will have access to new features for iOS notification and via Fusion. You are getting additional features on your old system without spending a single dime!
Again, I get some of the frustration, but let's also give kudos to a company that has made a real impact on the reefing community and continues to try to take the hobby to the next level.