At the time my reasons were simple and pragmatic and all derived from the perspective of the possible consumers of such a device.
First, I was convinced from what I saw happening in the panel space that thin TFT LCD technology was on it's way out. As an Engineer I'd been keep in eye on the developments of Organic Light Emitting Diode technology that was in my view going to be the screen technology to end them all. If not it than some variant of it, I also knew from the production processes of such panels and their amenability to running off of standard CMOS fabs that they could eventually be produced in mass at prices far lower than what is possible with TFT LCD. Also, because OLED's can be produced in a variety of substrates (from plastic to glass) the material costs were lower...to me this all added up to a really cheap and beautiful display technology being read for devices within the next 5 years (that was 2 years ago). But what devices?
Around the time that Chrome OS was announced the smart phone segment was all but one phone, the Iphone and it was eating all the cake. I knew that the manufactures of panels would be itching to provide high margin OLED panels as soon s they could produce them to the cell phone makers...a few of the panel makers (Samsung, Sony) actually make cell phones themselves. This product segment would be the first target but by the middle of last year I realized that a large size smart phone would provide a killer touch sensitive surface to enable a new class of uses and I wrote a blog post on the coming lappad attack early this year to signal what was to come after hearing of the Ipad rumors. Now 8 months later, the Ipad is out and is a wild success and rumors of multiple pads from other hardware providers are already alive. Most of them slated to run Android as the OS...an Indian company already has made the bold claim that it's device will eventually be produced for $35 each. The strong pressures on all the competing pads that will be out to have low pricing will make differentiating difficult..however, when comparing one pad with Android and another with Chrome OS there will be glaring differences.
1) Android can run local apps without need of a web browser, Chrome OS may not.
2) Android can run stand alone games, Chrome OS may not.
3) Android can tether to a pc as a shared storage device for file transfers, Chrome OS may not.
4) Android will have a massive collection of apps written, Chrome OS runs the web but the uniqueness of it's mobile nature is harnessed by more apps which it may not have.
5) Android can be used on all major cell phone networks thanks to all the versions out there, Chrome OS may not even enable cell based phone calls (though it may do app based if it has that)
6) Android is perfect as an embedded system and is already going into proposed TV's. It's the perfect OS to run touch based TV's to come on OLED flat screens. Chrome OS also is good but in a tv will lack the software and drivers needed for local interface to the hardware of the tv.
the main reason Chrome OS will fail is not because it will be bad or have some technical glitches it will be because Aunt Millie is going to walk into a store ask for a pad, be told the Android pad can do everything the Chrome OS can do plus half a dozen more things and production costs would not be any greater on the Android pad (though some companies might use the illusion of a difference to substantiate a slightly higher price)..in any event Aunt Millie is going to go with the pad that gives more over the one that gives less. I can see the Chrome OS maybe being useful to places where apps and all the bells and whistles of Android beyond the browser are specifically not wanted...say for use in libraries or other public uses but aside from that I just don't see it taking off. It will be interesting to see how things unfold.