It takes two to tango, remember the unions had a part to play as well. Some where more militant than others when it came to reform. Did Thatcher get everything right of course not, no one does. But by the same token not everything she did was wrong. And something needed to be done when she became PM.
So it's 1979 you've just become PM, the country is in dire shape. What to you do to fix it? Now know one knows if things had been done differently if the country would be in better shape today or if it would be in worse shape.
As for the Community Charge (aka Poll Tax) it was based on the idea that every adult in the UK paid. So every adult within a local authority would pay the same rate, which in theory sounds fair. (and if you were unemployed/ a student/ low income) you would pay less. The system prior to it and what we have now is based on property, so with the community charge you might have paid more because there was 3 adults in the house. Now of course like with any tax system it had it's pros and cons.