Then how come, at just an inch bigger, my Macbook Air runs OSX wonderfully? And honestly, the computer could even still be a bit smaller without any problems.
The 11.6" Air is two inches larger than the iPad, and it has more pixels than the 13" Macbook Pro. And you have a trackpad to click small buttons, which is twice as hard using a capacitive touchscreen. If the Macbook Air display was 9.7 or 10", the keyboard would have to be smaller.
There's a reason why an iPad can't be used as a legitimate computer replacement. iOS' stripped down nature creates roadblocks to productivity.
Well, for some people the iPad is a great alternative to a computer. Two of my relatives just ditched a PC and Mac for iPads. But they are retired and don't need to do four things at once. A tablet is also a great computer alternative for kids ~12 and under. iOS itself does not hinder productivity. If there was a 15" iPad with a decent resolution, Safari and Pages could be running at the same time side-by-side, and would work nearly as well as a Mac if a bluetooth keyboard was connected. And with iOS 5's multitasking gestures, switching between workspaces would be even more like a using a Magic Trackpad in Lion.
If that EVER happens you will see a mass exodus as me and every other professional ditches Mac OS X forever. I don't want a Finder with 100 Options as Buttons. That is just about the first HCI lesson you ever learn in CS "Don't pepper the screen with 4,000,000 buttons. 10 and a Menu enhances useability. Also, how am I supposed to manage all my complex project files? For a OS designed for a desktop that whole idea is ridiculous. Please explain how exactly Maya, or Logic Pro, or XCode or Final Cut Pro or Motion is supposed to work in this new world? How am I supposed to create an iOS Application made up of hundreds of files and resources and keep them organised with a Finder that will have so many buttons that to see them all I will have to have a single Finder Window at 5120*1440? And only then can I see my files?
I am in no way suggesting that all dropdowns should be removed from OS X and be replaced with a million buttons. I am only saying that there should not be universal File, Edit, View, Window, Help, etc. dropdowns in the menu bar. Applications such as Finder, Safari, App Store, iCal, Photobooth, Calculator, and System Preferences need no more than 1-2 dropdowns because of how simple they are.
As an example- Finder: The "Window" and "Help" tabs are entirely unnecessary. Under "Go", the only items that need to be preserved are "Go to folder" and "Connect to server." Those could easily be placed under a dropdown like the "Action" (gear icon) within the window. Most of the items under "File," "Edit," and "View" are already available under "Action" or are set as default icons (such as viewing icons, list, or cover flow). Do you understand the point I'm making? There are two ways to do the same exact things, and it just makes everything more complicated.
In iWork, Xcode, and Final Cut Pro you absolutely need many dropdowns to keep everything organized. But they should be within the application window and should have icons (along with or in replacement of text), they should not be on the Menu Bar. Even iWork and Photoshop Express for iPad have 3-4 dropdowns.
All windows being full screen doesn't mean that you can't have two or more windows on the same screen at once. You could have Xcode taking up 3/4 of the screen and Finder taking up the other 1/4, but just not be able to stretch windows from the corners.