That extends to relatively low-friction cases like Patreon. The number of podcasters and bloggers where I've thought, quite earnestly, "I really like what this person is doing, I should kick a few quid their way," and then just not done that is near infinite. And it's never because I was feeling stingy; it's because I couldn't be arsed.
First they want you to sign up for an account. Give a lot of personal data. Then set up a payment model, often recurring. Just to read one article? No way.
Micropayments will save some of that hassle but I don't want to have an account with every news site linked to by HN.
Half a cent per article is a plausible target for all the weak/cheap sources who can't possibly afford to put up a paywall right now because nobody would pay. It's not going to be used by the currently paywalled sites, their business model relies on getting a not-micro amount from each customer.