I agree about the general idea of not throwing stones into the sky. They have a tendency to fall back down on one's nose.
However banning tools that were 'snuck in through the back door' because of their efficiency and because nobody had the heart to follow the actual procedure to get them through the front door strikes me as profoundly childish. Especially if it is done as some sort of vengeance, or 'just because we can'. In fact about just as childish as throwing stones into the sky.
I'm being a bit idealistic here. There will always be turf wars in BigCos. But hey if some people switched from trying to look like the best and brightest to getting stuff done instead, i'd be all for it.
There is no place for idealism in selling to BigCos. You have to work through the process and build your case or someone else will steal your deal, possibly with an inferior product.
CIO's job is to manage massive resources and organizations - first and foremost to keep the critical line-of-business systems running. For most of them cloud right now is neither the top priority nor a viable substitute for core infrastructure. You are right on with your strategy to get foot in the door to circumvent their slow-moving processes. However you should be thinking of how to work yourself into their higher-level planning process instead of positioning yourself as adversary of their corporate policy by calling it stupid.
Just remember, the CIOs have the power to ban technologies that sneak out through the back door. Alienate them at your own peril!
EDIT: Whoever down voted this, please post an actual substantive rebuttal.