So Mac OS X inherited one userbase that appreciated platform-specific software. Haiku doesn't really have anything to inherit like that so until people start making Haiku-specific software, that could be an issue for seeing great Haiku software rather than just ports.
For a while, the OS X app space was rather "pure". A minimalistic aesthethic, plenty of small opnionated productivity applications. Apple itself didn't wreck or disrupt it too much (looking at you, MS Office).
Then mobile happened.