If you work in tech and get compensated with tech money and hold tech stocks as part of your compensation, then your net worth is already tied in a substantial way to tech as an industry. Buying more tech stock increases how much your net worth will swing based on tech industry trends.
Bigger risk, bigger returns. Oftentimes risk is opposite of the goal.
As long as you're aware of the interlinked nature of tech stocks in the tech industry, then by all means buy more, but if you're planning for retirement and you don't have a nest egg that's invested on lower risk with more modest returns, you might want to think twice about putting more eggs in the tech basket.
Why avoid a Apple, etc?