The level of insanity evidenced by this law is hard to overstate. It's so easy to protect onesself from being shot while breaking into another's home. Simply don't do it. Why on earth should the government protect burglars?
I believe that it's primarily because the government doesn't wish to admit that they are wrong in abrogating citizens of the UK of their basic rights to personal defense, and conferring those responsibilities entirely to the government. This is a foundation of Socialism, and to suggest that The People are to be trusted in this matter would represent, in the government's view, an ideological collapse.
It would also provide a precedent in questioning the government's other fiefdoms, such as healthcare. It would magnify the voices of those who are denied kidney dialysis machines because they are outside of a government-imposed statistical survivability demographic as well as a host of other people who are either denied or are suffering under restricted services of one type or another due to private industry and enterprise being shut out.
My great hope is that it won't be too long before the citizens of Great Britain will rise up en masse to protest and change these evils that are being inflicted upon them, entirely by the Left I might add. They have been beaten down for far too long and deserve far better than this.