feeding meat rabbits: scraps vs pellets

We are almost ready to start our breeding/meat efforts here (held up by the fact that our pair of does turned out to be a brother and sister, and I have been indecisive about who needs to be replaced. I think we're about to sort that out, though, and I'll just say lesson learned in the young rabbit sexing department....)

One thing that I've noticed watching the homestead people who talk about meat rabbits is that the rabbits are almost exclusively on pellets and hay and not scraps (which seem to be only treats), even in only small-scale production.
I started with the rabbits as a way to reduce my kitchen waste, and so far it's worked wonderfully. We eat a lot of greens and cruciferous vegetables, and so the vast majority of their diet is cabbage leaves, broccoli and kale stems, nappa cabbage, arugula.... I do grow fodder for them when there aren't as many scraps around, and we also gather weeds like dandelions which they love. The rabbits quite honestly maybe get pellets once or twice a week when pickings are slim (as for hay-- we also can only get either Tifton hay, which the rabbits don't like, or alfalfa, which seems to be overkill plus is stupid expensive, and I'd just rather feed them fresh forage). The rabbits are in great shape and we've had no digestive issues or diarrhea at all.

My question is: is there some reason people aren't using scraps/weeds/forage as a main food source for their meat rabbits? I'm concerned that it might affect breeding or meat taste or something that I haven't thought of yet.

Though I'm not raising them now, we did when I was a kid - and we did give them kitchen produce scraps. I think the main reason most folks don't is because if something you hit on, in your OP- it's inconsistent. In meat production, it seems consistency and ability to replicate results are the primary issues, but personally, I think you're doing it right! I believe your meat will be healthier for you, because your rabbits will be healthier. They need a wider variety than just pellets &/or hay, for complete nutrition, and I'd do it the same way you do, frankly.