A car is not a bike. Whatever happened to the concept of context?
The road is supposed to be used responsibly, driving or cycling drunk shows you don't care about that. Everyone here uses Taxi, public transport or friends for transport if drunk.
The pedestrian absolutely notices whether they were hit by a tonne of metal going 40mph or 20kg going at 20mph. Regulation should be proportionate to how much risk you impose on others. Given how many more people get killed by car drivers than by cyclists, we should be looking to make driving tests much stricter before we even begin to worry about regulating cycling.