Good as Meryl Streep is in the movie, the iron is missing somehow. As if it was her armour and not her core.
In addition, she was at the point of a conservative philosophy which was championed by many at that time. If the phallanx of support had not been there, she simply couldn't have done what she did.
Personally, I think she did a necessary job bravely - dragging the UK back from its excessively leftward drift. The trouble was, she didn't know when to make peace. At some point, you want the revolution to stop. Or at least, to dial down a notch or two. But Maggie couldn't do it.
It was her nature to fight and to keep on fighting. And in the end, she was fighting things the British people liked about themselves and their islands. The sense of compassion, of shared sacrifice, of society. She couldn't help but see those who opposed her as a sort of enemy to be crushed. When in the end, what seemed necessary was for the acceptance of difference, of a philosophy that welcomed nuance, that had some human warmth to it.
Her greatest strength was also her flaw.