I think I have a different definition of what 'inertia' means than most people. It seems like most people use it to mean 'do nothing' as in 'be inert', whereas I understand it to mean to continue going along the same path unabated, and if it so happens that nothing was happening originally, then nothing will keep happening.
So, I might say,
(1) 'I switched the telly over to Wimbledon and my inertia led me to sit on the couch all night watching the tennis'.
And that seems to fit both definitions. But if I say:
(2) 'the inertia behind Abbott's campaign to scrap the Carbon Tax ensured it became an eventuality'
Then I think most people would understand (2) as 'Abbott did nothing about the scrapping the Carbon Tax and so the Carbon Tax continued to exist', whereas I could easily read it as 'there was so much momentum behind repealing the Carbon Tax that it got repealed anyway, despite it becoming an increasingly unpopular move'.
What say you?