I agree with you that it is highly volatile and very expensive coin, but there is no obligation to buy the entire coin to trade. And if we talk about volatility, then which altcoin is not volatile in cryptocurrency? In my opinion I think altcoins are more volatile. And there is more chances of scamming. On the others side in bitcoin atleast there's no worry about to be scamed. So if anyone want secure and profitable investment then obviously should take bitcoin as first choice after that can choose alt-coin from the top pairs.