Consider the humble motorist who allows the cyclist the whole left lane to which they are entitled. In peak-hour traffic, this usually means crawling along at 10kph behind the flashing pedals until it is possible to change lanes and go around them safely. So far, so good. But are they grateful? Oh no! What do they do at the very next set of traffic lights, while you're sitting once more in the left-hand lane? Why, they overtake you ON THE LEFT and go to the head of the queue, meaning you're forced to repeat the overtaking process after every single set of lights.
Then you encounter a car parked in the left-hand lane. Thankfully a rare occurrence. So you've moved into the right hand lane and are preparing to go past, when suddenly the cyclist in the left hand lane decides to do likewise. But do they wait for the lane to be clear, or even signal their intent? Nup, just pull straight out, causing cars to duck and dive all over the place in order to avoid hitting them.
Once, just once, I'd like to have a passenger in my car, who could open the left hand door at every red light, just so no cyclist could fit past. But with my luck, and the arrogance I've seen displayed, the cyclist would simply go straight through it, then sue me....