The vast majority of people in the world live within walking distance of a small neighborhood market.
The only time I go for fresh broccoli is when making a stirfry or salads.
I can see why fresh would be better if you were planning on eating the broccoli raw or perhaps steamed, but since I mostly use broccoli in soup or stir fries, it ends up fairly thoroughly cooked. In which case I don't believe I would notice a difference.
I purchase frozen vegetables (stuff like brocc, cauliflower, peas, carrots) because they come pre-chopped, last near indefinitely so I don't have to worry about finishing them before they rot, and whatever amount I want at that moment can just be poured out of the bag, pre-chopped, into whatever (usually single pot) meal I am making.
EDIT: not trolling, i'm really curious. Fresh broccoli is available all year round everywhere and it is so much better than the frozen stuff. Why would anyone buy it frozen?