We say our battery's 'dying' or the site or something's 'dead' or 'live' or 'alive again' though - post mortem makes sense in that case, I understand the objection but I think you have to object to the rest too.
I agree it makes more sense, from first principles as it were, I'm just saying 'post-mortem' is consistent with other usages, so if we don't like it then we probably shouldn't like 'the server is dead' or 'the site is on its knees' etc. either.