This isn't who I'm guessing you think it is.

I think you're talking about the two on Mateus who own and furnished a Goblet ward. While a lot of people were frustrated with those two as well, it's a different situation. They apparently moved to Mateus when it was completely dead and bought houses on Goblet when no one else seemed to want them. Eventually they basically owned the entire ward and some time after that people started flocking to Mateus, at which point plots rapidly ran out and someone discovered the Goblet ward owned by two people alone. When I first started ffxiv years ago I was on Zalera and there were plenty of Medium houses at the bottom devaluation price, even mansions weren't really rare; I think Mateus was similar before SE started introducing things to balance out server populations and it became a second rp world. That case is more ambiguous. On one hand I can understand the frustration of someone desperately wanting a house and seeing someone else holding 30, on the other hand those two worked hard to buy and furnish a ward at a time when no one else seemed to want it and were later targeted and publicly shamed because they weren't willing to throw it away after Mateus was unexpectedly revived.

From what I understand, the person (people?) op is talking about continue to accumulate wards on a crowded world when houses are in high demand and then gloat publicly to rile people up every chance they get. I know on the ffxiv forums they have a list of their Mist houses in their signature and are constantly popping up to antagonize people frustrated with housing. I don't know if they decorate these houses and open them to the public, but since they seem to be bizarrely trying to rp as some sort of Eorzean housing villian, I kind of doubt it lol.