If you watch the presentation or read the transcript, they explicitly say that they're doing fraud/spam account prevention.
Do you really think you're doing more fraud/spam detection and prevention work than apple?
But also any argument that the makes spam harder to block also applies to Facebook or google logins - I can’t imagine spammers are using real email addresses with those services.
The only people this changes the experience for are actual users. Spammers already have a huge array of options to get “real email addresses”.