For all of those saying you are not PIC of a FLIGHT if it does not take off and land. Consider the following.
You are a mechanic and a SE pilot.
You are allowed to taxi multi-engine aircraft by virtue of your mechanics licence.
You decide to have a go at flying a ME (so you commence moving an aircraft for the purpose of flight)
You have an engine failure on takeoff, fail to respond to the yaw, slew off the runway into a ditch (never having got the wheels off the ground)
Was this a taxing accident or a flying accident?
Were you authorised to undertake this activity (you are not allowed to FLY an ME as PIC, but you can taxi one).
I think the regs are perfectly clear that the moment you move for the purpose of flight, it is a flight; you must be qualified and current to fly that aircraft. The reason the Regulator phrases the rule as they do, is specifically to identify that a flight has started as soon as the airplane moves (unless it is being moved with no intention to fly) and all regulations to flights apply.
On the other hand, should you log it? who cares. Should a 3 hour wait at the hold followed by a taxi back be counted for recent flight - No, of course not. Do you learn more from a 15 minute aborted flight than spending 5 additional minutes doing a circuit? Probably yes.