I guess you could call it that, since it requires WAAS in order to install in.
Sure, they were built for 100 flights each. The flights were also supposed to cost way way less than they do now. The current per pound of payload to space cost is 2/3rds more than what was estimated in 1970. The whole premise of the system was launching a shuttle every week, in order to spread the development costs. It takes roughly 3/4 of a million man hours to process a vehicle for launch. Sit down and do the math on how many people you would need to keep that launch schedule up, and the number of vehicles needed.
Basically, a single launch costs us 1.3 Billion dollars. Sure, the Space Shuttle is cool, but is it 1.3 billion per launch cool, I don't think so. Do we really need something the size of a DC-9 to take 7 people to space? No, we don't. Put them in a capsule, that is cheaper, and on top of a basic rocket, that is cheaper than the whole booster/ET/SSME combo. Heck, we've been through 4 entire systems of launch vehicles for humans, while the Russians continue to use the same basic core to launch people that launched Sputnik in 1957.
SpaceX has the solution, especially after seeing their Falcon 9 perform so well this summer. Hopefully things keep rolling well over there, and then maybe we can get people back up on our own rockets soon.