I think that's where the reputation comes from. Overcooked broccoli is inedible, and I know people who refuse to leave any bite to it at all, which seems insane.
I feel like crunchy, fresh broccoli is a relatively new trend. I found out about it on my own, at my place as a kid it always looked like green boogers and tasted the way you imagine that would.
I think it used to have to be cooked to hell because in the past it legitimately didn't taste as good as it does now. Selective breeding has taken a lot of bitterness out of many vegetables.
It got cooked to hell because most people can't cook and that's what they know. If anything broccoli tasted the better in the 80s, because it wasn't as maximized for shipping.
Like I said, we noticed with tomatoes and apples. And overcooked broccoli is still just as gross as it was in the 90s. One of very few foods that makes me gag instantly.
Also, we grow our own vegetables often, it's not like all my food comes out of a bag. We'd notice big changes, and we did notice the change in cooking styles around it. It's a generational argument in my family how to cook broccoli, not a change over time.
Vegetable breeders for the veggies that you get in a normal grocery store don't typically select for tastiness/flavor, they select for things that can maximize profits - hardiness, shipability, production, etc.
That and canned veggies. Don't know if it's because we were low income or if produce was just a lot more expensive back in the 80s and 90s. But, I remember eating a shit ton of canned "mixed vegetables" at my house and at friends houses.
My mom was a good cook, but I feel like we didn't get a lot of fresh veggies unless we were living on a military base where the groceries were subsidized.
My mom used to have a microwave cookbook and would make most veggies in the microwave oven. This cemented my love for crunchy cooked vegetables. I can't eat green beans in a restaurant because most of the time they are almost the consistency of porridge.
In almost all cases, I frankly detest steamed vegetables. Probably due to my grandmother steaming the absolute piss out of ANY vegetable when we visited. My mother didn’t overcook them nearly as bad, but to this day I just don’t enjoy the flavor of any vegetable steamed nearly as much as I do roasted in the oven. High heat + short time + delicious, crisp, lightly charred goodness