Because they were never going to pay you
for it anyway. If they were, and this is a category the author left out, they pay you anyway.
Subcategories include people who use free copies to decide if they want to buy a product, people who are reading the freebie while waiting for a paper copy to come out, and crowdfunding where folks read free stuff but have the option to sponsor more/faster/whatever if they wish.
The author is absolutely right that many people will pay for convenience over free stuff, if they have more money than time/energy or if the EROEI is better when paying. This is why my year-end collections are now spiralbound at Staples instead of hand-punched at home. Save us a day's backbreaking work? TAKE MAH MONEY!
Conversely some people will tolerate extra effort for free stuff because they have more time/energy than money. That's okay too.
The general rule is, make it easy to do the right thing and hard to do the wrong thing. Reward good behavior, ignore or discourage bad behavior.
In crowdfunding, I have noticed that giving away things is an excellent way to get more money. It's a little counterintuitive ... in a cash
economy. But it is the fundamental premise of a gift economy
. We say, "The gift must move." You don't just accept the goodies and pocket them. You give something to someone else, which can be a share of the first or the same kind of thing or something totally different. The idea is to keep the energy moving. A lot of folks in crowdfunding route part of their incoming funds back to other projects crowdfunded by someone else. I can only afford this sporadically but I still do it.
Another consideration is relationship. When people like a creative person, they will throw money
without even being asked. But if they feel their money is going to a big corporation instead of the author, they're less enthusiastic about that. They get downright huffy if they feel like they're getting screwed, not getting their money's worth -- maybe the prices are jacked up or the product isn't very good. So that's a big reason why some people pirate. It's not just an economic issue that people can't afford a product or feel it's overpriced. It's a relationship breakdown between provider and customer. Consider how very badly the music, movie, publishing, etc. industries have treated their customers. Well, now the bottlenecks are coming loose and people have other alternatives. Newsflash: if people hate you and get a chance to leave or hit back, they will TAKE IT.