This is a fair criticism, MonoTouch, Corona and other solutions have their place and are great solutions too. I reworded my article to avoid this unnecessary bias.

Having developed in MT and ObjC (but not yet bit the bullet on RubyMotion), I can concur that this statement is valid. MonoTouch was an emulation, making it at best slow to catch up and at worst a version behind iOS. It also had a fairly funky debug scheme, having to use IP and not the wire. Granted, you get the REPL in lieu of a debugger with RubyMotion, but given how incredible the REPL is, I imagine a debugger will follow. As for cross-compilation, that wasn't so much MonoTouch as MonoCross, something that falls in to "jack of all trades, but master of none." MonoDevelop may have autocompletion, but it was buggy as all hell for me, and RM is positioning itself as using any IDE, where MonoDevelop locks you in as Xcode does.

How long has it been since you used MonoTouch? I first used it a little over a year ago: debugging over the wire worked just fine (though you can debug over a network connection), the API was only ever behind on major iOS updates (it's also not hard to call an Obj-C API from MT yourself, without waiting for them to put out a new release of MT), and all the compilation was handled by command line programs called by the MT MonoDevelop plugin - you could call them from make/Rake/whatever, should you prefer to.

Doesn't MonoTouch use Visual Studio ... or is it something else?

You can use it on Windows, IIRC, but for Mac where VS is not there, you use the cross platform MonoDevelop IDE (+ XCode for parts).