The usual thing is for PPL's look down their noses at microlights and the homebuilt sector of flying. That is, until they find out that there is good flying beyond the spam can/GA school environment.
I couldn't agree more, but the microlight/homebuilt scene is not the only "escape" from the generally crappy spamcan / school rental scene.
Just buying a decent plane and flying to places is a pretty damn good escape.
The microlight scene delivers an escape towards lower cost, which suits very many GA participants who are willing to do a pretty severe tradeoff between cost and mission capability.
But not everybody is strapped for cash, and the benefits of the microlight/homebuilt scene are for ever limited to VFR i.e. relatively fine weather, and (short of considerable hassle) flying within the UK only, which is likely to result in flying the same old burger runs.