Why Don't We Like Dollar Coins?

If the treasury switched from paper dollar bills to exclusively producing dollar coins, it would save us $5.5 billion according to a GAO report. but every attempt to roll out a dollar coin recently has failed.

Is it the size? The dollar has to be larger than the quarter. Does that make it too big? The Susan B. Anthonys weren't that bog. Neither were the Sacagaweas. Nor the present presidential coins. They are a bit thicker, but are they really uncomfortably bigger? Why won't we embrace the dollar coin?