The scheme behind the lack of downwards compatibility was always a pain with OSX. It's great for the app developers because they can offer you a paid upgrade to a new compatible version. But UX wise it's so bad it makes you consider moving to another OS. I once had ProTools on a MacPro and found it out the hard way. I thought I could just upgrade to the next OSX version like with almost any other OS. But after the up…
Killing 32 bit support is going to cost me about $600 per year, because I still have a pre-CC copy of Photoshop, In Design, and so on. I am absolutely furious at Apple for this.
It's the same logic.