He's not advocating piracy at all.
Correct. Piracy is downloading software that you haven't paid for.
People are allowed to backup their software. How you obtain those backups isn't that important. It's not piracy if you already own the software, although the website that you use to obtain said software could be accused of piracy, since we don't know who's downloading what from it. I've heard similar arguments for downloading roms. P2P is nothing more than free, unlimited, unregulated, public cloud storage.
But where he's wrong is that games still use CD keys.
Well, not in the same way that old games used them. Nowadays your cdkey is tied to a GFWL/EA/Bioware/etc. account, which IMO is illegally violating the first-sale doctrine. A lot of download services do offer downloads with a retail key, but nobody offers full spectrum support. It's a few games here and there, across different services. It's better to just wait for a steam sale, and repurchase your collection on the cheap. Over the years, I've repurchased a large portion of my physical collection over steam using this method. It's just not worth the hassle anymore, ever since microsoft made things worse by trying to manage your software with GFWL and Games library. It's also made me question the validity of the $60 price tag, especially since there have been numerous articles stating that the ideal price point for PC games is $40, plus you can't resell account tied software. I won't pay retail price for any game that's tied to an account, or ships with DLC. The loss of rights and value is not worth it, and we aren't subsidising console hardware. Skyrim in particular is one game I'm not purchasing until a price drop, even though it's been on my wish list, plus I have too many unfinished games to play, including oblivion. Right now I'm enjoying Cave Story+.