Education - sure. The only purpose these masses can serve is acting as genetic pool for picking the best and uplift them through education. A permanent caste-like system is doomed as next generation of it won't be as performing as the previous one. But we have to understand that only a small majority - a few percent - of the poor will be uplifted. The rest has to be kept at bay in one way or the other.

As for fortress thing - you are exaggerating. There isn't so much crime around these days, much less than 30-40 years ago when things were still going fine according to the article.

In the end, it's just the technology change. 40-50 years ago uneducated masses who were members of solid middle class have been factory workers. They are automated away. There isn't anything which could be done about this. Besides, exactly 40-50 years ago, during Jimmy Carter era, same things were said about farmers who found themselves displaced with great improvements in farming productivity. History just repeats itself.

And yes, classes must be sustainable and moving between them should be difficult, only through exceptional personal (genetic) abilities and a lot of effort. Otherwise they are not classes, just people gambling and some of them winning.