Yeah, intentionally or not, it does happen. In light of the latest Apple 'innovations' I would also look at Grey's law (just look at what a piece of shit ITunes is). There have been numerous class action lawsuits in the past years, which I agree, don't prove anything except for the fact that consumers do notice that their older devices often degrade to not being usable.
Anecdotally this is how I lost my 2012 MacBook Pro. The hardware was excellent but software upgrades made it almost unusable. Browsing was ok-ish but I ended up using it mainly in 'terminal mode'. I couldn't find a Linux distribution that ran properly on it so one day I decided to go with El Capitan because of it's focus on 'performance' and that it's hardware requirements were compatible - MacBook Pro Mid/Late 2007 or newer. It worked fine but two days later I fried my video card while reading a PDF in Preview. I'm not saying the upgrade fried my computer but I was really frustrated I only got 3 years of use out of a superb (and expensive) piece of hardware.
And yes, after using an Asus for a few (awful) years, I bought another Macbook on which I'm writing this now.