Both are very different operating systems with different approach to granting processes access to hardware resources. Approach with which ActiveX is built on Windows raises serious security concerns on a Unix-based OS. It is basically software written for a single-user OS that now you want to port to a multi-user OS. On a multi-user OS, not all users have equal privileges when it comes to hardware access. Marketing/sales concerns aside, portability is probably the main reason why there's no ActiveX for Mac.