Most ICOs are scams and most altcoins don't have a working product or a feasible route to getting one. Spending your money on these projects is simply gambling - they aren't worth anything, let alone the millions of dollars some are valued at. You are relying on future newbies to sell to in order to make a profit.

Bitcoin, on the other hand, is a working product and is used in the real world. Its price is based on growth and adoption, not pure speculation. It's the best bet, rather than throwing away your money on some scam.