Thatcher and Thatcherism have become the paradigm of Conservativism. They've gone so far beyond what actually was. Effect gets muddied with intent, political views with personal views. Discrete professional choices and comments become retrospectively amalgamated in some over-arching personal profile with which we can hang and quarter Margaret Thatcher.
Re: the UK's economy, the thing is we were never going to be able to compete with the BRIC countries in terms of manufacturing in the long term. Primary industries like mining were already effectively dead, secondary industries were doomed, and much of the economy of the North East therein.
This is another myth. Many of the industries were in a slump in the late 70s/early 80s, but all
industries have peaks and valleys. German governments routinely subsidise industries that are in just as bad situations as our mining industry was, and even though they sometimes made losses on it in the short term, now they're reaping the benefits because, unlike us, they actually have industries to keep their economy afloat. Whereas the UK, because Thatcher dismantled our entire industrial base, now has nothing to bring the money in now that the financial sector, on which we were totally dependent, has now been milked dry.
(And again, before someone shouts at me: the Labour government are also to blame for not repairing the damage Thatcher did and rebuilding the industries she destroyed, but it doesn't change the fact she was the one who set us on this course.)
The only fact I can see is that our economy was on the perennial slide and Thatcher's concerted transformation has ultimately impacted the economy for the better in the long term. Her de-regulation of the City, making London the Financial Capital of the world, our GDP actually increasing faster than most of our European compatriots for the first time in two hundred years. In fact - aside from Germany which has a fundamentally different economic model (i.e. they have a current account surplus, the UK has always been a borrower) we're pretty much in the best situation now in most of Europe, when you look at the bigger picture. The economic crash of 2007-9 isn't Thatcher's fault, we had her inept successor and a very strong labour government since then.
It's also not true to suggest the economy was always booming even when Thatcher was in office. Even going just on the GDP figures (and ignoring unemployment figures which are obviously even grimmer for Thatcher), throughout the whole of the 80s pretty much, the economy was stuttering, usually either in recession or growing slugglishly, with the exception of a brief boom in 1986-87. It was only from about 1994 onwards that the economy started growing consistently strongly -- but, if Thatcher somehow gets credit for that success that happened after she'd left office, then why doesn't she also deserve blame for the economic failure that eventually happened in 2008?