Or you could do exactly the same thing by buying the mutual funds that had the best recent performance. Hint, that's not actually a winning strategy, past performance not reflecting future results and all that.
I have never run or worked for a mutual fund, but I have heard that funds have way more restrictions over holding periods, leverage, and other constraints that individual investors do not have. Are there mutual funds that swing or day trade? Most individual traders can liquidate his/her entire account without really affecting the market. Large and medium sized mutual funds can't do that. Besides that, I would think it would be harder managing other people's money than one's own. There are pros and cons to both sides, but investors will start bailing out of a mutual fund that can't beat their benchmark. Are there many traders who run algorithmic trading strategies that are consistently profitable month after month with excellent Sharpe ratios?