That is exactly what I wanted to point out. Oftentimes such privatization is buying short time benefits from the future. In my opinion, Britain has sold to much of its assets and is carrying a huge burden today.
Many things Thatcher did were terrible, but at the same time (for example) it's difficult to argue that a national government should be in the business of running road transport for the country[1]. There's a reasonable argument that some utilities work best in state ownership in some cases, but many of the other things that were run by the government prior to Thatcher were complete disasters.
[1] http://en.wikipedia.org/wiki/British_Transport_Commission