Firstly condolences to those involved and also to those at CVT ATC whom no doubt feel pretty shaken.
There does need to be a debate at an appropriate time, probably on another thread regarding CVT as Pprune Towers eludes.
The approach to 23 is in open airspace through a corridor of traffic that routes north to south via the Lichfield NDB east of BHX and west of EMA. On the other side of the M1 there is Husbands Bosworth, one of the busiest glider sites in the UK. As a regular user of this airspace, you need alot of eyes to keep a good continual watchout and CVT can be found to be busy.
Extending the class D controlled airspace towards Bitteswell VRP maybe one recommendation that comes out of this tragedy.