No its not like USD, because USD is centralized currency.
Bitcoin is not centralized and that is the main difference.

You are saying/observing  that altcoins can be manipulated because of Altcocins/BTC pairing, but you must understand that all kind of pairings will always be available for manipulation and without pairing you cannot determine value of something.

Also keep in mind that even fiat currency has some kind of pairings, for example USD  to gold reserves.