Market makers aren't competing with buy-and-hold investors. Price fluctuations like this don't affect people that are investing in the fundamental performance of the underlying company. The price may swing by a few percent randomly in either direction, but in the long run, a growing company will have a growing stock price.
Equities make up much of my portfolio and I haven't been disappointed. As cynical as everyone is about how "big companies suck", they have historically done a pretty good job creating value. And I think that will continue for some time.