The comment states the why clearly when read within the context of the article: "I'm clearly no longer the target demographic and their corporate goals aren't aligned with mine as a customer any more"
I don't think they did.
The comment seems like an emotional nostalgic conclusion they have after watching the WWDC, without any mentions why they think future will be worse than what we have now or what we had in the past.
Pity though, Snow Leopard was something to be envious of.
For me personally, the ability to upgrade RAM and storage, and graphics card on a desktop are central to a professional workflow, and part of my purchasing decision as a prosumer.
Coupled with a million other issues I've had over the past few years, including reliability and support, I no longer feel the added cost of a Mac versus a Linux machine is justifiable.