I dunno, it seems a dramatically more reasonable response to preventing accidents than the disaster that is PTC[1][2], which has cost billions and will probably never work properly.
Works just fine on the NEC, where it's been in use for over a decade. The real problem is that this was a huge unfunded mandate imposed by Congress on the railroads, both public and private, which is why they've been less than eager to meet the deadlines. In some particular cases, notably Caltrain, it's been a disaster, but that's because they decided that they have totally unique requirements and want a totally custom system rather than going with either of the relatively proven solutions.