Chiming in a little late here, but I play on 1823 and this type of behavior has not only killed the server population, but deflated any fun the remaining players have.
We can’t attack or destroy the structures as it is PVE-C and we can only fight them, player versus player - which they crave and love. It would be giving them what they want.
We are stuck dealing with a situation that should be punishable (in PVE/PVE-C) - as should be the trapping in of bases, and spamming of foundations across the map. We literally have no way of hitting back. Yes, we could drag bosses over there - but all we would be doing in reality is serving up skeleton keys as they 5 or 6 strong at lvl 60.
Not only are they blocking off the obelisk, they are extremely vulgar in chat - it’s repulsive. A number of us have reported that behavior as well, with no avail. Having the mute/block function actually work in game would be wonderful.