The pins aren't enough.
The two chainrings are specially designed in a pair to make the chain mount on the bigger chainring easy and ultra fast.
Its not only marketing, it works amazingly well.
The drawback is that changing the chainring sizes isn't possible, you must stick to the standard pairs 53-39, 52-36 or 50-34.
As said all big brands, Shimano, SRAM, Campagnolo have their own commercial name for that, example:
latest Campagnolo XPSS