Cant stand the things myself, but for my own reasons. However the biggest complainers to Microlights appear to be Pilots of other types of Aircraft who have no clue as to their capabilities and requirements. No excuse for not obeying the Airspace rules, but I think if one looks at their normal enviornment they will find its not as reckless as mentioned here.
Main problem I see is that they are so easy to fly that a lot of the guys flying are not properly trained as to the rules and the dangers of low flying etc. and dont have the experience of flying into or around controlled airspace. Sort of an "Offroader" with wings.