Most of the paths around here do not have a centre line marked and this may be part of the reason so few users keep to the left (which is the "correct" side in Australia)
Suppose I am cycling on such a path at a moderate pace, the natural tendency is cut the corners, i.e. to go close to each apex to make my track as straight as possible.
If I fail to notice a faster cyclist coming up from behind just as I enter a corner, (and he fails to sound a bell or issue a verbal warning), does he have a legitimate grievance that I have "cut him off"? Or is the situation similar to motor racing that I am entitled to take the line I have committed to through the corner and the fellow behind is obliged to keep clear?