CBTC just doesn't work

There has been a fad in the transit and railway world to abandon the conventional signalling technologies that have worked so well for the past hundred years, in favor of "Communication Based Train Control". This is a centralized system wherein, basically, every train constantly tells the central control computer where it is, and the computer tells the train how fast it should be going. Generally, these systems are highly proprietary, and often parts become obsolete soon after they're bought (San Francisco, for example, has a system based on OS/2). And the systems are generally very bad at handling vehicles that either don't communicate, or don't meet the criteria of the often-finicky systems.
As if that wasn't trouble enough, some bright fellows decided that rather than use the proven but expensive inductive loop technology, they'd use radios to communicate with the trains. Inside tunnels. Which tends not to work so well, and almost all of the systems where they've tried that have failed, including the Jubilee Line in London, the BART, and now Philadelphia, where the "more advanced" system has in fact reduced capacity and caused delays. Will they ever learn?