Sure, they wouldn't want to, but they could. To take his point to a higher level: it would be much more destructive (in several senses) to have to rip out HFS+

Sure, they wouldn't want to, but they could. To take his point to a higher level: it would be much more destructive (in several senses) to have to rip out HFS+ for legal reasons than it would be to rip out Xcode. Lots more people depend on a filesystem.