I thought the story about that was satire. It couldn’t possibly cost a quarter million dollars to put up a mechitza.
And you are correct, there would probably be no need since you could just use different sections of the stands which are unconnected.
But, as far as your contention that it isn’t “halachicly necessary,” I don’t really understand why you think that only things which are “halachicly” necessary can be a good idea. There are plenty of gemaras which say that it is a good idea to do all sorts of things which are not “halachicly” necessary. In fact, I can recall a case where a beis din was mechayev someone to pay something that was not halachicly required.