varjohaltia | Online Publishing, Piracy and Wizards of the Coast

So, WoTC has decreed that nobody can sell its old books as PDFs anymore. That's the only electronic format available. They claim they're worried about piracy.

So, before yesterday, if I wanted an older WoTC book, I could
1) Go to the library. WoTC makes no new money.
2) Buy a used book on Ebay/Amazon/Flea Market. WoTC makes no new money.
3) Download a pirated copy off the internet. WoTC makes no new money.
4) Buy a legitimate PDF. This has the benefit of being legitimate, searchable, and good quality. These accounted for 20% of sales, according to RPGDriveThrough and Paizo. WoTC makes money.

Today, if I want an older WoTC book:
1) Go to the library. WoTC makes no new money.
2) Buy a used book on Ebay/Amazon/Flea Market. WoTC makes no new money.
3) Download a pirated copy off the internet. WoTC makes no new money.

Now, I'm not a business major, but does this make sense? What do all the methods left to readers have in common?

Mind you, a lot of other publishers have the issue of not selling older works -- perhaps they are just being business-stupid, or they don't want to cannibalize their new sales. The difference is that they didn't make these things available, and then randomly pull them off the market after seeing that they sold well.