It's a very, very anti-armed forces comment. I may disagree with it, but it's a completely valid point of view to hold. The idea that the armed forces, whose job it is to kill, is above this sort of criticism (wishing death, hellfire), is pretty mental and actually quite worrying.
Imagine Major General Snodgrass says "we must go to war with Russia now and hang it if it's nuclear!" Someone responds that Snodgrass is an idiot, a fool, a bounder and trying to compensate for the fact that he is slightly less sexually attractive to humans than a badger that was hit by a lorry last tuesday fortnight.
Snodgrass will have medals and be described by establishment types as a "National Hero." It goes with rising through the ranks. Also likely upper class for students of the British class system. Prosecuting people for being critical of a national hero who supports the class system is a thing some dream of seeing happen. This is a step forward for them.
Again I don't think it's right that all UK soldiers are evil and am generally opposed to killing in any circumstances where there's a viable alternative. The idea that expressing the other side of such an opinion should cause you to be prosecuted is insane on every level.
I've heard that the most celebrated holiday throughout the world (albeit on different days) is "Independence from England." Death is what soldiers deal in as even the armed forces most strident supporters will agree. It's the whole point, otherwise they'd be aid-workers.