Why not invest more in the Healthcare sector? (opens in new tab)

I have reviewed dozens of healthcare Mutual Funds and ETF's and compared them to the major indexes (mostly S&P), as far as back in the 1980's. It appears that the healthcare sector has always outperformed the general market by quite a lot, being in the double digits in annual returns most of the time . It even appears to have less losses than the general market during market crashes. Knowing that in the U.S there is little chance of major political disruption on healthcare, why isn't this sec...