Not an expert by any means, but it seemed to me that a lot of UK politicians were basically waiting for Brexit to conclude in whatever fashion (Deal/No-Deal/Bremain/Magical-Unicorn-Salvation), at which point they would dump all the blame and political fallout on May and boot her to the curb. Now she is showing herself the door before the end, so whoever gets PM next will have to take the role of blame-sponge. Who would actually want that job?