[BNB] Binance Coin as collateral

what are arguments against BNB being a collateral in MCD ?

It is a token which price is quite decoupled from other assets (like Bitcoin / ETH) and have significant Market Cap.

Are there some cartelisation risks due to the pact that most of trading of BNB happens on Binance?

Since April 23 BNB is no longer an ERC20, its being moved to its own chain. Also it has a terrible distribution with a Gini Index very close to 1.0.