> It sounded to me like the audacious part was that they don't make it clear that, once you sign up for this service, your users cannot get your podcast in any other way than using Apple Podcasts…
You definitely can.
What the author said was, "What I learned is that Apple does not produce an RSS feed for podcasts that they host". But this is misplaced outrage on the author's part, since Apple has never produced RSS feeds.
Every other podcast hosting service in existence provides RSS feeds. But unless you've already done your homework and you're starting a podcast, you don't know why not having one is important.
That's not a comparable situation. Spotify sign contracts with successful podcasters who they pay(> $100 million in one case) to produce content for their platform.
The argument here is that by offering a "Click here to start your [not really a]podcast" button, Apple is suckering in people who don't understand how Apple's iDevice-only offering differs from every other podcast hosting service.
