As long the iPad runs iOS in its current form, it will not be any more pro than any other device out there. The surface is 10 times more pro for anyone not only doing "writing, reading, viewing, manipulations using simple inputs like sliders and pointing/clicking at/on stuff".
Take the FTP example above, I would never use an iPad for that, i would use my macbook pro and automate it. Every step of it, i.e. i drop file into folder, it gets automatically uploaded and manipulates any files on the targets server.
On my macbook I have full control to do anything I need, I am not on Apples mercy of what is allowed nor is there any limits on what is possible. The iPad is like a sandbox in a world full of possibilities.
I fully agree, using the iPad as a MacBook replacement is simply a practice in futility. The biggest issues I have with iOS is the way it handles files, apps should never manage their own files. There needs to be some sort of file/document management system in place in which handles all files, storing them in a central location. There also needs to by a single file system UI in which every app uses to open and save files. As well as the ability to log into your cloud services and use them as if they were local assets.
Another problem I have is not being able to run 98% of my apps in the background, the iPad Pro has 4GB of RAM, I should be able to use my terminal app in the background, as a programmer I need to be able to start a compile jib and let it run in eh background. Apple could easily implement an Android like feature where the user can control how many apps are able to run in the background at any one given time.
External monitor support, everything about this feature in iOS is just simply horrible. The iOS desktop isn't displayed at native resolution or aspect ratio, nor can I extend the desktop, just mirror, also the DPI looks resiculous as in it's huge. This is a must have feature for me as I carry around a portable display with internal display for my MacBook 12. I also would like to use the iPad Pro as a desktop computer, the way it is now though, it would be impossible.
Mouse support, yes, mouse support. When the iPad Pro is plugged into the keyboard I don't want to use the touchs Display, especially when I'm using my desktop Apple keyboard as I like having the iPad Pro pushed back a bit making navigating the UI almost umbearable. Tim Cook even said that laptops with touchscreen's are a failed concept because the user has to reach over the keyboard to use it, well Mr. Cook, what do you think is happening when a person has a keyboard connected. It's uncomfortable and frankly not user freindly, also using a mouse for editing code is just a must have me. Now I can add support for this by simply installing a mouse driver when the iPad Pro finically get's Jail Break support but Apple should just add this in, even if they only allow mouse support for when the keyboard is plugged in is fine with me as it's the only time I would need it. Yes, I also know that the new Apple Keyboard has a touch cursor but I'm using the Logitech as Apple's keyboard doesn't have the much needed function keys, backlight, isn't as comfortable to type on and doesn't protect the iPad Pro in any way, it's also extremely flimsy.
The list actually goes on and on but I'll leave it here. The iPad Pro is fine as a consumption device like it's little brothers but I personally couldn't use it for anything else at the moment. Hopefully this will change in the future.