Smashington,

I think there are too many variables to consider here. For example, with PvP and housing they may indeed have put forth considerable resources toward something that not many people are yet using. However, all that work has established a foundation and I think many more people will participate in them as time goes on.

With housing, they've designed mechanics that will be used in individual housing (and more people will use FC housing as they save up money/prices are reduced.) The same has happened in PvP, they now have the mechanics in place for Frontlines and whatever other PvP activities they choose to add later, which will certainly draw in more players. So at this time it might not seem like the effort is worth it, I think the future will change that.