A number of questions arise, of course. Does finance employ the same people that worked in factory floors? No. Is finance sustainable in the long term? I doubt it, as it is much more mobile than manufacturing (Germany is attacking the British stronghold in finance). Would manufacturing decline anyway? Possibly; in the US it did, but in Germany it didn't. In the end, it is always a game of what-ifs.
Anyhow, I'm not in the position to have a sustained opinion on Thatcher's policies. I was way too young, and did not really study British history from the period. I have no idea if they were positive or negative overall.
She did have a plan, though. I wish current European leaders had one too, beyond "let's grab what we can while the Titanic is going down".
Overall, the big change with modern politicians isn't so much that she had a plan as her willingness to take radical actions that weren't part of the plan or some near-consensus view
The actions taken towards the communities she "restructured" since her premiership seem to show evidence in favor of the latter. If thatcher and the tories were really concerned with improving the country as a whole, they would have taken action on the long-term systemic problems with our workforce (education etc) and given the communities they destroyed something to do between then and now. Instead what they did was simply replace the industry with foreign financial wizardry, while leaving the workers to rot. 30 years later, they use the gap in achievement between these two groups as a stick with which to beat the poor even harder.
And that's the last I'm saying on this subject today.