The tall grassy perennials, do they have to be cut down in spring?

I like to leave mine for winter interest then cut them back to about a third their height in the Spring. Sometimes I'll go a bit shorter as long as I don't disturb any new growth coming up. I was told that if you don't cut back the grass I have it will go to seed and it would damage, maybe even kill the plant. I'm guessing it's a hybrid thing and not sure if it's the same for all grasses, but I haven't noticed anyone else who hasn't cut theirs back.

Yes. To about 10 to 12 inches in height.

I do