After thinking on this a bit there are 3 major issues going on here. The first is that at $50 U.S. there simply isn't enough value. 3 workers are valuable, but the price tag is over the top for a majority of the player base.
The second issue relates to the first, and basically is that as a paying customer I don't feel appreciated. I've spent over 100$ in the year or more I've played the game, but I don't see or feel any good will between Nexon and myself due to this issue. Unfortunately this feels like a piracy update, and for all the wrong reasons.
Last is the inability to acquire the building through other means. If it opened up in later ages, or was otherwise acquired through game play then fine, however that isn't currently the situation.
TLDR; it's too expensive, the playerbase feels taken advantage of, and there are no alternate means of aquiring the structure through normal gameplay.