I know some Scots through first marriage and they detest her and I don’t understand why. I think she’s awesome.
In the early 1970s, the British government held an inquiry into 'devolution' - the idea that Scotland and Wales (and to a lesser extent Northern Ireland, the Isle of Mann, and the Channel Islands) would have some sort of self government, all the way up to independence.
The Report recommended Scotland be given its own legislative assembly.
The Scots wanted this and in 1978, the British government held a referendum to establish it. This referendum achieved majority support for the idea but failed because of low voter turnout (it got 51% of the vote, but the terms of the law that set out the conditions said that 40% of all Scottish voters had to approve it, as well as it achieving a majority of those who actually voted, and because of the low turn out, only 33% of all Scottish voters cast a vote in favour).
This helped to bring down the Labor government because the Scottish National Party withdrew its support and voted with the Conservatives in a motion of no confidence. Margaret Thatcher and the Conservatives won the resultant election - and the Scots believed that as they'd given her government (as they saw it) she should give them their own government - especially seeing former conservative Prime Minister, Lord Home (Alec Douglas-Home), a Scot had promised they would during the Referendum campaign. He had no authority to make this promise - he hadn't been Prime Minister for 15 years, and he hadn't even been in Parliament for 5 - but the Scots still felt that Margaret Thatcher had broken a promise to them.
During the 1980s, the Scottish steel industry more or less collapsed. This had little to do with the Thatcher government - it simply wasn't competitive in the world market anymore - but again the Scots blamed Thatcher. Finally in the late 1980s, Thatcher introduced the poll tax into Scotland, a year before it was introduced into England and Wales. Hugely unpopular all over the country, the Scots were even more angry about it because they believed it had been inflicted on them as an experiment. In actual fact, it was imposed there first because the existing system was known to be more unfair in Scotland than it was in England and Wales, and it was considered unfair to make Scotland wait for reform simply because proper evaluations hadn't happened in England and Wales yet (there were genuine problems with the way the poll tax was implemented - but this wasn't one of them).
End result - the Scots have come to believe that Margaret Thatcher destroyed their economy (untrue), unfairly taxed them (no more or less true than anywhere else) and denied them self government (true) which she'd promised them (untrue). And she is hated.