BTW: I voted for Labour in the end: I couldn't bring myself to vote Tory; ended up knocking on doors for 3 days for my Labour MP and continually spamming the Conservative facebook page. Our seat is marginal, so fingers crossed.
Key reasons were her refusal to debate Corbyn 1on1, her tacit support fro Trump over climate change and Mayor of London, and her decisions as home secretary with regards terrorism and police. She is not 'strong and stable' and I think she is an intellectual lightweight.
What I found interesting is that May would have called her snap election because Labour voters like me professed we were fed up with Corbyn. But when it came to it, May was simply not inspirational enough to desert Labour for. And as Corbyn spoke more, so he sounded like the real change the country needs. So I stayed. And I suspect millions more like me too.
This was the swing May was counting on. But she failed with millions of wavering labour voters, hence, she will get a reduced majority - I'm convinced ot it.