You can load plenty of nukes on a dropship.
Even a Heavy ASF.
Ultimately, it's the universe/game system that it doesn't fit in; With the thousands of worlds, even large scale use of nuclear weapons would not necessarily result in casualties that anyone making the decision would miss. The WoBs Asteroid Bombardment vessel, if it exists, was a WMD in the modern sense. Using a nuke in a space battle where the worst result would be the destruction of a few ships you wanted to see dead anyways isn't in any way morally objectionable all by itself.
What I expect to see, however, are armoured jumpships; Well, I don't actually expect to see them, but they would make sense of a sort.
I think we're derailing the thread. :D
How would you go about a modern variant?
Reduce the laser broadsides by one each to add a few small SCLs and LAMS? Might be able to resuse the energy feeds and heatsinks.
Well, and maybe plaster on 50 extra tons of armour.