Those kind of changes tend to come when a large percent of the population is fed up with the way things are and start to agitate for changes. At that point, it's unlikely to happen progressively... So it's a bit of a catch 22, as long as the people who benefit from the current state of society are in power (or control those who are in power), change are unlikely to come progressively since it would be disadvantageous to them but, once they lose the reigns (as they inevitably do), change happen so fast that it's both potentially bad for the society at large and worse for the ones who used to be at the top.
I'm not sure there are many examples of enlightened robber barons who allowed progressive changes that were counter to their interests but improved society as a whole.