Cause altcoins are way too cheap than bitcoin. And it also give you more opportunity to gain big profit though you need to take some risk on investing on alts.  By the way I can suggest you 1 alt that will give you good profit If you hold some of it. Try to check Privcy I believed that this coin has a big potential in terms of value and uses. Maybe this is not the 1st privacy coin exist in the crypto world but It is worth trying for.