I might agree with that assessment if they had established another monarchy. You can say it wasn't a conventional revolution, and for that time you would be right. There was nothing "conventional" about it. It was a revolution unlike any in their recent history - even in that it was revolutionary for the time.
I don't get your point. The British monarchy had not exerted much control over the colonies. They had been left to develop self-government through an evolutionary process over a period of a century and a half. When the King and Parliament tried to tighten up and exert more control, the Americans revolted. Thus the "American Revolution" was conservative. It was not a case of a people who had been under a powerful absolute monarchy, as in France, suddenly overthrowing that system and trying to fabricating a new one from scratch, and tearing apart traditional all traditional authority, including that of the Church, as in France and Russia. Those were real "revolutions."