First, it's actually not that simple :) We tried out like a whole lot of podcast clients (30+ I think) and 'are recognized by most podcasting clients' is certainly not true. That's why we recommend the following to client developers: If your OS allows it subscribe to the OS default (which is often pcast://) but also define your own schema (like mypodcastclient://). This allows us to have a 'Open device default app' link that on Android shows all installed clients that subscribe to pcast://, but also to specifically start a client with its schema.

Second, 'It also doesn't get any easier than just offering the naked RSS feed.' is also not true. We talked to a lot of people and subscribing to a podcast is a nightmare for people that don't get (and don't want to get) the concept of what an RSS feed is. And copying and pasting links from a webpage to an application is already an obfuscation (and a real pain in the ass on a mobile device) for the 'normal' user, so why not add a more user friendly obfuscation :)

However, the button is an experiment and we'll see if and how people will use it. Until now the feedback from podcasters and listeners is nothing but positive.