More and more I see incentivized tweets verified through the scraper route. I imagine tweet postings will similarly go through a more brittle bot based route.

The advantages of an open and easy to use API are to avoid these hackish solutions and to corral would be spammers and other purveyors of low-quality content into easy to monitor channels.

Charging for API access makes it harder to analyze would be spammers. While legitimate users of automatic posting like the author are further burdened by setting up their own bots.

That said, one of those API glue sites probably offers a still working RSS to tweet feature.