Most chip manufacturers do this, but usually the extra silicon is disabled because that section has failed quality gates - the same thing happens in GPUs, they know the top n% will withstand higher clock rates, so they put those in the expensive cards.
This is new because Intel knows that silicon is good (or else they couldn't sell the upgrade), but intentionally disable it. People are upset because they feel like they aren't "buying" anything, it's just a perceived tax to get what already exists (I'm not saying that this is a fair perception, only that it's what most people will feel - I think this is a plan doomed to fail)
It's much older than that. The tale is told, at least, that in the 1960s, IBM sold a model of 360 that could be upgraded to a faster model by flipping a single switch. They charged many thousands of dollars to send out a tech to flip the switch (if you did it yourself, I presume it would void the warranty).
