It's all in software development.
I see it as similar to our work, as soon as you get used to something, workout all issues and bugs and nail all those pesky bugs so you know exactly where are you by just having one look at the files, .. they change version of software and introduce 10000 more bugs you never heard of and it's all over again.
They change CPU to completly different architecture (X86), means software has to be recompiled for new CPU arhitecture at least if not completly redesigned if it was designed with stuff that exist only on those chips (e.g. Altivec, G5 optimisations, etc..).
I am actually glad as this might make or brake Apple (hopefully first).
You might have some 3rd party software developer give up and say go Windows only as it has the best development tools out there and so far it was sticking with same CPU architecture, while Apple is switching architectures for the second time now
