Conation Or Simple Negative?

Halliday & Matthiessen (2014: 576n):

Note the incongruence of the form people failed to accept her, meaning ‘people did not accept her despite her efforts’. Here failed to is functioning as a simple negative, such that there is a proportion

she was not accepted : people did not accept her ::
she failed to be accepted : people failed to accept her

Compare examples such as I sent them a letter but it failed to arrive, the banks failed to support them. These should perhaps be interpreted as a form of enhancement, meaning ‘do negatively’!