The good side is that with zsh and some other software getting their place in OS/X; Linux and OSX communities will diverge away from each other. I kind of like this as a Linux user and developer. With OS/X or Apple we share so little in principles (read a lot of comments here), vision and development(now) and it is good if we end up being 2 mutually exclusive ecosystem similar to Windows/Linux.
Being a former Apple employee and having enjoyed Apple's ditching of the classic Mac OSes for OS/X, both worlds have had pretty much similar environments. After 2012 the Apple and Linux development communities appear to be totally accelerating in different directions.
For Linux and OS/X, noone said they share common parent; the shared common tools such as bash, samba and a lot of stuff removed as mentioned by this article will create diverging ecosystems (and before replying watch out, noone says diverging kernels).
Being a former Apple employee and having enjoyed Apple's ditching of the classic Mac OSes for OS/X, both worlds have had pretty much similar environments. After 2012 the Apple and Linux development communities appear to be totally accelerating in different directions.