Many investors like altcoins because there is a profit on investing into it, most of the altcoin will follow btc bull run there are altcoin that rise very fast when the bull run begin  that is why if we invest on dip and we get lucky from our investment and the price rise ten times higher then we will earn a lot from our small capital, bitcoin is so expensive now a days and it is very risky so many people prefer altcoin than btc.