Catalyst only runs on Catalina and up. Also, it would take me weeks or months of work to get it to work correctly (it's not just check a box like Apple advertises) and it wouldn't be as good as the current Mac version. 70-80% of our user base wouldn't be able to use it because of Catalina and those who did get the automatic update suddenly would have to learn a new app after years of using the current version. On top of all this my revenue go down now that the price if the iOS version includes the Mac version. It doesn't seem like a win for anybody.