[mimon]

Survivorship in what sense? The castles that exist today have not survived because they were better at repelling swordsmen, they survive because someone in the nobility happened to like them and protected them from development and hundreds of years of disrepair.

[mnw21cam]

In England, it's more the case that the castle survived because the occupier didn't do anything to annoy Cromwell.

[goodcanadian]

Indeed, Cromwell tried very hard to destroy castles. The trouble was that they were very hard to destroy. Most of the ruined castles are not in that condition out of neglect; that was simply the "best" they were able to do at destroying them. Eventually, the cost of gunpowder was just too much to continue that campaign.

[KineticLensman]

Yes. Like Corfe Castle in Dorset, which was taken by treachery, and was demolished some time later, when the fighting was done. [0]

[0] https://en.wikipedia.org/wiki/Corfe_Castle#Post-medieval

[bluGill]

Nobles who died defending on a staircase that advantaged the attacker don't leave family behind to care for their castle.

I don't know if it is true or not, but your explanation doesn't seem to hold up.