He is absolutely destroying WordPress. I wasn't ever a fan but given that 40% of websites rely upon it, the end users are the ones who will suffer the most here.
If somebody doesn't fork WordPress soon, it will be decades before WordPress is purged from the web and in the meantime a lot of those remaining sites will devolve into bot-net members and malware hosts.
Because that's how Mullenwegs crusade is going to end: With the death of WordPress.