Of course, someone would have said the same thing about IBM a few decades ago, or Internet Explorer 8-10 years ago. And they were saying it about Yahoo and Altavista and MySpace before Facebook and Google came along.
Sure. And they did say those things. And the sites that genuinely cared about user needs, both past and present? They did the 'inefficient' thing. They optimized for whatever was best-of-breed at the time (IE, FBConnect) for ease of use, then found a way to also cater to whatever came up next. Many headaches were caused by IE/Firefox incompatibility, but Firefox is still gaining marketshare today.
Well said - I would argue that what is at stake here is far more immediate than any of the 'fights' mentioned above. User choice in the examples above refer to service use. In a war for the social web, what is at stake is the way user identity is represented online.