Zlin 526,
You are rather naive about the abilities of the firefighting at a special cat or cat one airfield.
The easiest comparison is between how the local authority fire service would deal with a car fire, which would be of similar scale to a light aircraft being on fire.
The local fire service would send one appliance carrying about 1800 litres of water and a crew of four. It would probably take them about 5 minutes to bring the fire under control, assuming it was well alight, and 10 to extinguish it.
Now take the equivalent, a light aircraft well alight at your local small airfield. Out goes the Cat 1 airfield Landrover. The CAA stipulate it need only be carrying approx. 200 litres of water and 2 crew, who have had 2 days training many moons ago. Due to the materials used in aircraft and the flammability of avgas, the plane will burn quicker. It is unlikely the crew will be able to control this fire let alone put it out.
Any small fire in an aircraft, or indeed a car could be put out by a couple of DP extinguishers, does this need a licenced field? Probably not. Anything bigger, well unless you have the facilities of a larger airport...no chance!
So we should all operate from big airfields? No, it would be too restrictive. But lets not pretend the provision at a CAT 1 airfield would be much use either.