Think it was a bit of both with her. She never quite came in for the criticism she deserved at times - but recently the wheels had quite clearly come off and she'd gone from a prospective future PM to a fairly isolated regional leader who'd simultaneously been humiliated by the fact that the new PM was literally the one person she wouldn't throw her weight behind for leader.
It's really interesting to see some of the misconceptions surrounding her at UK-level though. A lot of the discussion over her acted as if she was this statesperson-in-waiting who'd been undone at the wrong time, but the reality was she was never anything more than a vocal opposition campaigner, an effective means to boost the Tory vote in Scotland but someone who was fundamentally never going to be anywhere near power.