Excactly, when we are talking about conventional explosives.
Flashbangs are effective inside closed space, where the shockwave and the light can effectively... distract... enemies and make them temporarily unable to fight back. Outside, the effects of a shockwave itself are limited to very very limited area, and shockwaves in general do nothing against armored hulls of war machines.
Against living enemy, shrapnel is the most effective because it has a wide area of effect (120 mm mortar grenades have an effective kill radius of 100 metres if I remember right, and artillery grenades have even larger but elliptical area of effect). However, shrapnel, like shockwave, can't do much agains armored targets, so unless it's a direct hit even artillery can't do much against panzers.... direct hit on the roof *will* destroy a tank for sure, but that's quite far-fetched and nigh impossible to achieve.
Against armor, shaped charges are the way to go. Instead of releasing shrapnel they have a copper cone ahead of the charge, the open side of the cone pointing towards the targed. When the charge goes off, the explosion starts from the point of the cone, sending the point of the cone on its way forward at very high speed, and when the explosion proceeds towards outer edges of the cone, the cone becomes a sharp tipped piercing cloud of extra-hot fast copper particles that go very deep into RHA armour steel. This technique is used in every AT weapon there is - AT missiles like Javelin and Eurospike, and recoilless rifles.
When we talk about nuclear detonations, the shockwave indeed causes most destruction on wide area. On ground zero, however, the shockwave doesn't matter the slightest bit because it is formed there. The radiation heats everything around it into very high temperatures, melting and even vaporizing much of the matter near it. In the very center of the explosion, there even exists matter in plasma state, at least if it's a fusion bomb we're talking about.
This super-heated matter expands very rapidly, which creates the huge shockwave.
In space, the only matter the bomb has to heat is itself, and while it still would form an impressive shockwave of superheaded gaseous radioactive metal, that shockwave would disperse quite soon.
The most destructive part of a nuke in space would be the intense radiation that would vaporize warships' surfaces quite measurably, of course depending of the distance. But I guess FS and FS2 era ships are so hevaily shielded against radiation forms that it just has no effect.
So, I conclude that Freespace nukes and anti-matter bombs utilize one form of shaped charges, but instead of having a simple copper cone in the front of the charge, they probably consist of three parts:
1. The back portion of the missile, behind the payload. Contains propulsion and trajectory units.
2. The charge, either a nuke or anti-matter one.
3. Front cone, containing the piercing matter - possibly it even contains some anti-matter in itself. Also contains guidance systems.
When the missile reaches a point where it's still perhaps less than metre away from the target, the charge(s) detonate. The back portion of the missile is probalby constructed to reflect a big part of the detonation. One way to achieve this is to make the back portion very heavy, so that the detonation can't easily push it backwards, and thus more energy can be directed forwards, where the target is.
The lighter part in front of the actual charge plunges forward, becames a fastly deteorating cloud of superheated mass, and plunges through any hull structure imaginable.
If the front cone of the missile contains anti-matter in magnetic stasis, the magnetic stasis is destroyed when the cone hits the target at high speed. The anti-matter, though, still has momentum forwards, and it continues to go through the parts of the cone it meets, and eventually the hull of the target. On its way, it would react with ordinary matter in quite a destructive way.
Either standard piercing or anti-matter piercing would work, but AM has the advantage that ordinary matter just cannot be protected against it. It just destroys any kind of hull it touches, so only way to protect against AM is to get more width and mass onto hull, so it lasts longer under anti-matter attack, and the anti-matter cones can't penetrate deep enough to actually get through the hull.