That is because there is one key difference between individuals and large institutions. Namely, individuals pay taxes on their gains while institutions generally do not. Some investment management firms have responded to this change. Others have not. Obviously, no portfolio manager will want to exclude one potential source of money, so it will take a little work on your part to see which mutual fund may be right for you.
Turnover is the largest source of increased taxes for investors.
Turnover is the measure of the amount of active trading in a portfolio. Funds with high turnover are run by active management. Active managers often buy and sell securities based on their perception of relative value. If a stock held in the portfolio increased a significant percentage, then the stock may be sold resulting in a large gain. But that gain results in a taxable liability.