1. scared of selfish mining
2. shares selfish mining possibilities

   The major disincentive is that their revenue would take a nosedive as Bitcoin crashed as a response to their actions.

3. assumes miners are suddenly irrational without really backing it up (except that a podcaster doesn't know what to do in such a case)

   But why would they have any reason to believe this would happen?

4. but they're only irrational if there isn't another coin

   That's where a zcash knocking on the door comes in handy.

this would be a lot more interesting if you weren't naming another coin, which you probably know, so this will set off everyone's shill bell and rightfully so.