You should see how they harvest lavender. If I were an anthropomorphic plant I'd probably loose my lunch after seeing one of those videos.

This is my impression of why we can get away with this. Annuals tend to gamble with weather conditions. There's enough seed bank stored up from previous years that if a scouring windstorm breaks all of the stalks in an area, then the seed bank can help recover next year, and if that's not enough then some seeds will blow in from the edges eventually, and ten years from now you can't tell.

Perennial plants have to be sturdier. Only some, such as alpine species, are adapted to drop damaged limbs. They are used to being jostled by hail, storms, and herd animals, so the insult is less permanent.

I don't know how that translates to perennial grasses, except that most such grasses can and sometimes do burn to the ground, and regrow each year from rhizomes. Half the plant survives each growing season, and the other half is sacrificial.