Those figures might be true only for the US/North America, but worldwide Symbian has almost 45%, RIM a little under 20%, iPhone just over 15%, and Android just under 10%.
(As of Q1, 2010, pre-iPhone 4, source: http://www.gartner.com/it/page.jsp?id=1372013)
No one seems to mind their MP3 player monopoly because the iPod was so much better than the alternatives.