Most of the people I know are buying altcoins because they're "cheap." They buy it at a high and sell it at a low. I'm just getting bitcoin, no alts for me.
To some extent, I agree with buying and holding bitcoins for value. However, you should be able to profit from these moments when the price of bitcoins decreases in favour of altcoins. They are not cheap fiatwise, cheap with respect to btc. Hence good for a short term investment.