I don't understand why you would feel slighted, this is just a business partnership (albiet a large one) and no different than when Microsoft offered $500, 000 in azure credits to YC companies. There are certain perks to joining an organization of entrepreneurs and developers, this is one of them.
I think that's fair to point out, but it's an order of magnitude difference (especially in the context of the other comp'd services YC companies get in their first year or two).