It's worthy. Bitcoin is must have currency in every experienced investor's wallet. Crypocurriency market is based ob bitcoin. All altcoins are pared with bitcoin. Even if you are sceptical of bitcoin and you have to buy altf first of all you need to buy bitcoin (in most situations). That makes him most usefull coin on market at this moment.

Bitcoin also is making all altocoin price. Yea. Thats why "altcoin prices imitate bitcoin move on market". Take a look at one of your altcoins. 80-95% of its volume is pared with bitcoin. So if bitcoin price drops your alt have to drop too cous in 80-95% it price is dedicated by bitcoin.