Brocoli just isn't what it used to be....
Some evidence that there's less nutrients in modern vegetables:
Declining Fruit and Vegetable Nutrient Composition: What Is the Evidence?
"1) early studies of fertilization found inverse relationships between crop yield and mineral concentrations—the widely cited “dilution effect”; 2) three recent studies of historical food composition data found apparent median declines of 5% to 40% or more in some minerals in groups of vegetables and perhaps fruits; one study also evaluated vitamins and protein with similar results; and 3) recent side-by-side plantings of low- and high-yield cultivars of broccoli and grains found consistently negative correlations between yield and concentrations of minerals and protein, a newly recognized genetic dilution effect."
Add to that the fact that our produce travels an average of 1500 miles to get to us and loses nutrients as it travels, and yep, Grandma was eating much more nutritious veggies than we are.
"Right is right, even if no one is doing it; wrong is wrong, even if everyone is doing it." - St. Augustine
Even w/o the studies to prove it I know the broccoli I get at the farmers market is way better than the stuff you buy at the supermarket; they are intensely green little clusters, full of flavor. When you eat it, it feels like there is still some life force left in it, and of course this is even more palpable when picking food out of your own garden or gathering it in the wild.
Another reason I grow my own broccoli. And cauliflower. And spaghetti squash. And Butternut squash. And onions. And Tomatoes. And sweet potatos. And asparagus. And pumpkin. And beets...