Not really wanting to get into this argument, but thought I'd correct a few things.
First, the military does use ANFO and related explosives. In fact, because of it's lower expansion speed, ANFO is preferred to C-4 for a cratering charge. C-4 is preferred for breaching.
The reason is simple, if one considers the difference between, say, a high-powered rifle and a shotgun loaded with 00 buck.
C-4 would be less likely to push down a wall or roll off a column. The speed of it's shock wave is too fast. Instead, it will tend to cut and break.
ANFO, on the other hand, is the blunt object to C-4's scalpel. It will push as much as it breaks. This is why it's used for cratering charges. It won't do as well against hardened structures (like, for example, a reinforced concrete bunker) but is perfectly adequate for taking down normally-constructed buildings.
As an aside, it's also the same type of charge used to remove bridge abutments.
SGT Brister
U.S. Army
68W (Medical Specialist), 25B (Computer Analyst), 21B (Combat Engineer-this means part of my job is blowing up things with explosives)