Business owes its CURRENT customers and CURRENT stockholders. That's how business works. Apple owes nothing to the guy that owned an Apple II a few decades ago or a PowerBook a decade ago. They person gave Apple money for a product/service and received it. The transaction is over. The original owner is under no contract to continue to use Apple products and Apple is under no contract to do continue making products that suit the needs of that person.
In general I have to agree with your post, however, Apple however did have a professional circle with FCP7, and with Logic Pro X. They lost the FCPX battle, they didn't with Logic (yet).
Still, if you plan to abandon a whole professional segment that depends on your services, has paid and invested in an eco system, its at least decent to give a fair warning. If they don't have professional computing in their timeline, they should announce it, so people can adjust.
Half-assing releases and letting people wait and just giving them
a little something to keep the market segment is not ethically questionable.
Quartz Composer had a significant following and circle of user, and its obvious its being phased out. That's fine. However we only know that because Apple has been ignoring it since 2011 (and as of 2015 is unsupported on iOS devices).
They killed of Aperture, but at least they gave a fair warning and a decent period of updates that bring it up to speed so you can comfortably readjust your business. They didn't give **** to FCP users. FCPX was a ground-up reworking that doesn't fit existent workflows and hardware of professionals (!) not to mention is not backwards compatible *at all* (3rd party makers sold FCP7 to X project translators).
I'm not saying FCPX is iMovie Pro, or that something is wrong with it. But they did an overhaul of something that requires a different workflow and aproach, made it incompatible with a lot of hardware and third party software (in which a professional company invests), etc.
With Logic Pro X, at least I can still use my Mackie Logic Control (since version 5). I'd be pissed too if I invested in hardware, software, just to have an update that changes fundamental workings come out of nowhere.
They're free to ignore the professional market, and I can understand why, at least please give us a fair warning and a chance to adapt, not blindly wait when the next Apple Pro App will be killed off.