There are lots of really cool and practical weapon systems that don't get built. One of the major reasons is versatility.
One "negative" about larger weapon systems that use KE as their means of kill is the inability to "tune" the payload. Compare that to a slower munition that relies on a chemical energy kill mechanism. Those can be tuned for armor penetration (HEAT), anti-personnel (HE, HE Frag), or somewhere in the middle (HEDP).
Toss in a desire to to beyond line of sight targeting & course-correction & guidance, and the super-fast, but laser-beam like trajectory of KE -kill munitions lose out to slower, but more flexible chemical energy-kill munitions lots of times.
Perhaps some future, as yet designed & deployed launchers/systems will be able to both sorts of munitions.
Fun stuff, trading off all these things. I wonder if there are jobs like that anywhere?
Actually one advantage of late-deploy KE impactors is the ability to tune for the target. The concept I had for the warhead above is based loosely on the AHEAD controlled frag round, and similar to that used in PAC-3 in operation (against aircraft, it actually doesn't have a warhead per se) among other systems.
Another one, the LOSAT missile was both KE AND (hence its name) beyond line of sight and was designed for course corrections.
The dominant reason why KE isn't used for longer ranges (rods from god notwithstanding) is the inefficiency of MAINTAINING a KE suitable velocity for long distances. That being said, there are numerous KE-like (or KE enhanced) munitions that are low speed until just before impact, and accelerate, various runway penetrating munitions for example.
Besides, you are splitting hairs, HEAT, HEDP, and SFP warheads are all KE, as is any fragmentation device, and in many cases use the same type of "propellants" (single-base rocket propellants -are- explosives, and double-base or composite ones use many of the same materials, and advanced propellants share the same development paths as advanced explosives...CL-20 in particular). It's purely a matter of the timeframe over which the chemical energy is expended, when it is expended, and whether or not it is focused via structure (rocket) or shape (HEAT).
