Those niche cards are really good though. Menagerie is worth buying in almost every game, as is Peddler.
That was my reaction as well. Particularly for Fortress - odds are you'll want it just as a village, and if there's any kind of trash for benefit it's absolutely bonkers-good (the Grim Parade recommended set being a fun example).
To me a "super-niche card" would be something like Masterpiece or Beggar.
To answer Teamlyle's closing question, a corollary to "It can be beneficial to score if it prevents your opponent from building further." is that in multiplayer, people are going to buy VP earlier, so you have
very limited time to build. Continuing to build the first time I hit $8 usually works, but trying that twice has always ended in losing badly since there just wasn't enough VP left to catch up.
Identify any key card(s) that are likely to pile quickly, and make sure to get your share of the split. Example, four player game, Port is the only village. Opening Port is totally reasonable in that situation, since it's the limiting factor on how good your engine can be, and they will run very quickly. That game, the two players experienced enough to know that opening with a normal village is generally bad didn't, and ended up with only two Ports apiece. We lost rather convincingly.