This ain't true, at least for the original iOS Google chat solution. It was a deliberate bet to do it as a web app, instead of a native app. I was there and disagreed, but I still understood the willingness to make that bet.
Google Voice app was started later than the original web-based Google Chat for iOS project. The latter was already released and in use before Google Voice app was blocked. It wasn't made as a reaction to that dispute.