You don’t need HCK for entering the dungeon. Another player could give you the enter item as well (would be to harsh for a PPU e.g.).
You need HCK to loot the Cyborgs for example.

It would make no sense you have to hack in the tunnels, or in the wastes, but not the cyborgs in the new dungeon (at least to me).

No Dungeon should be doable by one individual.
And by speaking of access to all content: a tank can’t access the HN for example.

So, where is the problem that you would need at least one hacker in your team?
As a HC Tank for example you don’t spend points into HCK, but they’re still a needed class in different dungeons.

I have no problems to change things, but only if it makes sense - And „I can’t play it alone“ is not really a good reason to me.