Accepted payments for token sale should be limited, all coins are competitive so they just need to use which is the top Currency such as eth and btc how they accept others. They have own coin to promote. And how could they accept multiple coin if it just a problem to use in transaction. They just need few but large in quantity
The project simply chooses the most stable coin, in their opinion, which will not be very volatile and they can safely use this money for development.