Absolutely, it was a huge strategic misjudgement.
However, her lack of awareness about the surge behind Corbyn was matched in the opinion writing of nearly all the pundits. Their distorted perception was caused by the rapid change in the relationship between traditional media, the internet, politicians and the public—and amplified by their personal incentives.
It was shown after the election that a previously unprecedented proportion of voters weren't accessing traditional media at all. The end of the Murdoch era.
I agree May is a poor politician and I have zero sympathy for her current predicament. She seems to be an awful person. I'd go further and say the entire Conservative party since Cameron hit the deck has been a shit show. Cameron and Osborne were economic idiots who've held their whole country back by a decade. The current lot seem to be a pack of talentless, intellectually insubstantial clowns. They're so focused on the fractures in their party and how their own career trajectories might be affected that they're capable of apprehending little else.
On the bright side, story seems to be the same in the US, France and Australia at a minimum!