Accept 1 or more than 1 cryptocurrency as payment in ICO do not help an ICO project succeed. It's just a kind of attract cause there are so many guys are not holding BTC so it's a little bit complicated for them to invest in ICO project which only accept BTC as payment, it'll be much better if these ICO projects accept multi cryptocurrencies but you should know that if it's a good ICO project no matter if it only accept BTC or multi cryptocurrencies, investors will try their best to invest in these ICO projects asap.