Under NAS we had a system where VFR were very close to IFR jets in E, but this was not regarded as an issue because there was no breakdown of separation, as no separation was required between VFR and IFR in E. Prior to NAS, the airspace had been class C and separation would have been applied - tell me which is safer?
Sorry to use the initial words in the next para, but I have seen a regular correspondent to this site use them.
"I was told" that due to the above non-incidents and the lack of a proper safety case, lawyers told Airservices that they would be liable for any mid-airs that occurred in the NAS airspace - hence the rollback of NAS - not just frequencies on a chart. RIP PF.