The problem with the iPad in my eyes isn't the mouse vs. touch issue. Yes, you want the UI to be designed for touch, on the other side the iPad now also supports a mouse.
The thing is a quite different point: the availability of software and the interactions. The iPad limits software to the App Store and its very restricted rules. Which makes the iPad nice for tasks which can be done completely inside one App, if that App exists in the first place. But it is really bad at any work flow which would involve multiple programs and a lot of programs aren't even allowed on the App Store.
On the Mac, one is free to run any software one wants, it is very easy to write your own. If it only is a quick shell script or python program. And it is trivial to combine multiple software in one project, just access the project directory from all involved programs.
There seems to be some capability of sharing file space between apps on the iPad, there is a great Git client called "Working Copy" which I can highly recomment which can interact with other apps, but that is quite an exception. In most cases, Apps on the iPad don't really support free data exchange with each other. My pet peeve: you cannot even add your own music to the music player on the iPad. It is sitting uselessly in Files and I can't access it.
