It really irritates me too, and I use a bike for my daily commute.
If I'm walking on the pavement and see a cyclist coming towards me, I always do my level best to get in their way. If they object, I just ask them if they're scared of using the road, or point out that they don't look 15 (the maximum age you're legally entitled to cycle on the pavement I think). That usually shuts them up.
There really is no reason to do so - my view is that roads are for wheeled vehicles, and the pavement is for pedestrians, end of.