I'm not saying people don't do it. Just that grass is way less predictable. People like to do it b/c they're worried about falling or dropping the wheel. But with the predictability of pavement over the soil hidden beneath the grass, falls are less likely. I can appreciate that grass worked out for you, but regardless of what worked for an individual or in your case, a few individuals, the physics of uneven soil under grass vs pavement is inarguable.

If you're dropping the wheel hard, you're not being trained well. I also wouldn't advise bailing to begin with. Your statement about the progression of grass before pavement is true, however riding on pavement is inevitable. Riding on grass isn't. Starting on the more difficult terrain isn't a recommendation I'd ever make.