Do you visit Denali National Park and think wow, look at all the weeds? Plants that grow naturally are not "weeds." Your lawn is an artificial environment, just like pavement is, and YES all lawns are destroying the natural ecosystem. You proved it in your own words, "grass turf is the best weed prevention." Those plants you call weeds and seek to destroy? That's the natural ecosystem. It's beautiful without your intervention/destruction, you've just been socially conditioned to believe otherwise. 

Lawns surrounding homes began as a patches of penned-in grass for livestock to feed on; land only the wealthiest farmers could spare. So, they became status symbols, which continues today, promoted aggressively by the massively profitable lawn care industry.

Try a paradigm shift. Visit a community like Girdwood or Talkeetna and check out all the little cabins in the woods without traditional lawns. Are they ugly? Hardly. It's possible to own a plot of land that's beautiful AND natural.