[FraKtus]

Two basic APIs are not available in 64 bits: Carbon and QuickTime. Steve Jobs promised to port Carbon to 64 bits when macOS X was introduced. So many of us developed for Carbon, and a few years later Carbon was deprecacted, and Apple announced they would never port it to 64 bits. Even software from Apple such as iTunes was built and Carbon, and it took years for Apple to remove the Carbon code out of iTunes...

[saagarjha]

You’re forgetting the part where this was long time ago. You’ve had at least a dozen years to migrate your code to Cocoa.