This guy is so wrong. Truth is that innumerable closed source programs are abandoned (and that's actually what "abandonware" stands for). However, contrary to open-source, they're nowhere to be seen.

When you're depending upon some piece of closed source abandonware, you're without recourse. If by any chance, you'd be depending upon an abandoned open-source software, most probably it has been abandoned because there are better alternatives; or in case there aren't, you're still free to salvage it from oblivion.

The whole article reeks of bad faith.