At Pursuit Cycles we don't build "Trailer Queens", we build bikes that are performance tools meant to be ridden hard. That means our riders get out there no matter the weather. And if your weather is wet, you'll want fenders - more importantly - your riding partners will want you to have fenders :)
When designing our frames, we worked hard on maintaining beautiful and elegant lines. One of the ways we achieved that is with our rear seatstay yoke. It provides a smooth transition from the seatube to the seatstays. But there wasn't an attractive way to mount the top of the rear fender.
Traditionally fenders mount to a "stay bridge" that spans between the stays. But in our case, we don't have one because it would detract from the beautiful lines of the frame. So our solution was to make a removeable stay bridge. That way we can maintain the beautiful lines of the bike when there is no fender, and when there is, you don't really even notice the bridge.
We also use threaded inserts for the strut mounts on the dropouts. That way when the fender isn't on, you can simply install a small stainless buttonhead bolt, and you hardly even notice it's there.
Fender mounts require extra time and cost when manufacturing, so they are a $250 option. But if you ride in wet conditions, they are worth every penny.