Tenure is not the problem. See this book:
http://www.amazon.com/Faulty-Towers-Tenure-Structure-Education/dp/0945999895
I get that tenure makes people jealous, but serious study shows that it is not the problem these arguments suggest. There are more hidden benefits than costs.
More recently, Michael Young spoke about tenure, again asserting it is not a problem:
http://wtaw.com/2015/06/17/new-texas-am-president-visits-the-faculty-senate/