It's different because what Amazon blocked, if his post is the full story, is purchases IN THE FUTURE of NEW content for his Kindle. How is that some evil taking back of things he thought he'd already paid for? It's not. He can still read all the books and content he's already purchased -- he just can't read anything new.
If you want to make a comparison to Home Depot, it's as if you bought a lawn mower, then returned it fifty times for this or that warranty repair, and they got pissed off at you, thought you were a whiner and a parasite, and banned you from buying accessories for the mower from their store.
Now, to make the analogy complete, we have to imagine that the mower is made by Home Depot, and you *can't* buy accessories elsewhere, so your mower will be a lot less useful in the future than you thought it would be. The action by Home Depot hurts more.
But I'm not seeing how any of your imagined property rights on your mower have been violated. You can still do what you damn well please with the mower. HD isn't restrictign your use of what you already own in any way at all. They're just declining to sell you additional parts that would make your mower still more useful, and I don't see what's wrong with that. Requiring them to make business transactions with you forever just because they did so once is obnoxious. Imagine if it worked the other way around -- if the law said that, once you bought a mower from Home Depot, YOU were required to buy all your future accessories from them. Suck much? But that's the forced-marriage deal you want to force on Home Depot. It fails the Golden Rule test.
I don't doubt that this guy is unhappy because he counted on being able to buy content from Amazon in the future for his Kindle. But...well, maybe he should have thought about that before returning SEVERAL $1000 pieces of big electronics. I mean, if doing business deals with him ends up costing Amazon money on the whole, instead of earning them money, what the hell did he expect? Why would they want to continue doing business with him? In essence, he's a "defective" customer, not working as they thought, and they're "returning" him. If, as he says, it's Amazon's fault, because they keep sending him defective merchandise, well, then he ought to be just as happy as Amazon that they're severing their business relationship.