Margaret Thatcher's strength was as a conviction politician, driven by a belief in the qualities of self-reliance, hard work and determination. It was these qualities, applied to herself, which propelled her to success, created her appeal and defined what it is we now call Thatcherism. Margaret Thatcher's weakness was a failure to recognise that, admirable thought these qualities are, championing them in isolation is not sufficient to create the basis of a healthy society and economy.
It is currently fashionable to ask why it is that Britain, unlike Germany, no longer has a flourishing manufacturing sector, especially since right-of-centre politics in Germany, best expressed by the current Chancellor Angela Merkel, mirrors much of the Thatcherite values. The reason is that socially conservative Germany, unlike socially conservative Britain, did not make Thatcher's mistake. German leaders, such as Helmut Kohl realised that while it was a mistake for the state to control large swathes of industry, this did not mean that the state should surrender its role in entirety to a deregulated free market. Successive German governments have recognised that, even within a free market economy, government, capital and labour are three legs of the same stool. British governments, on the other hand, have seen their role as taking one side or the other in a battle between capital and labour - and no-one joined this battle more furiously than Margaret Thatcher.
We now know that you cannot simply roll-back the state, remove 'rusting industries' and deregulate labour and financial markets in the belief that you are thus creating a pristine space in which the virtuous qualities of individualism will flourish, drifting in on the beneficial winds of the free market. As any gardener or farmer will tell you, you can prepare a seedbed, but unless you sow it with something and then tend to it, all you will end up with is weeds.
The last 30 years have shown that if you pursue a Thatcherite approach, as admirable as its values might seem at the time, all you end up creating is a society which allows the most aggressive and self-interested to reach the top of both politics and business. A society which has a denuded sense of collective interest or responsibility, a society where everyone is compelled to be in it for themselves, a society where wealth is associated with virtue and poverty is a sin. And also a society which doesn't have a car industry.