Wise words. Personally, I think the overreaction regarding her is for a combination of two reasons.
Firstly, she was the leader of the conservative party, which became very unpopular in the 90s although they are recently seeing a resurgence. They have a reputation in our country of being 'stuffy' and favouring and representing the middle class rather than the working class. They're traditionally the most right wing or capitalistic party, which meant if you were successful in life, great, if not, not so great.
Secondly, she is a female. I get the impression that because of this, any mistakes she made are magnified... it's almost like women aren't allowed to make mistakes now we've given or trusted her with the job. She did well to last as long as she did, and like her or loath her, that is testament to her strong leadership qualities. She took over a country that had virtually grind to a standstill and brought it kicking and screaming into the 21st century. She was ruthless, she had to be. The working class man didn't like it, especially as she was female.
It will be interesting to see how Obama does if wins his election. I think he'll be in a similar position to Thatcher, where any mistakes he makes will be magnified and he'll be under much more scrutiny than anyone in the past, much like Thatcher. Where they differ though, is that Obama appears to be more an inspirational man, rather than a man who will make tough unpopular decisions, though who can tell...