However one of the problems which it raises is that the majority of the GA fraternity [glider, parachutists, hang gliders, microlights etc etc etc] have traditionally been opposed to controlled airspace of any kind. The military have also opposed any hint of increased controlled airspace even when intended to protect the interests of commercial air transport and airports. The above groups want freedom to do as they please, a minimum of licensing requirements, a minimum of nav equipment in their aircraft and a minimum requirement to converse with ATC!
Perhaps there is some justification for their opposition.
When controlled airspace is being proposed it is usually stated that there will be minimal disruption to GA traffic and that all that is wanted is a known traffic environment to enhance safety for commercial traffic. All very reasonable. However, once controlled airspace in in place then priority is given to traffic using the airfield which it is there to protect. Other traffic wishing to transit is then allowed access 'subject to controller workload' which in practice means 'remain outside controlled airspace' more often than not. It is not possible to plan a flight crossing controlled airspace because there is no guarantee of being able to fly the plan, and often a very low probablility of a transit. Another issue that can arise is only being offered a transit at an altitude that requires instrument qualifications - not held by most recreational pilots.
When one considers the low traffic volumes at some airfields with Class D airspace and their reluctance to provide glider & GA transits it is not a surprise that GA is against further expansion.