I've been to many schools where TD's and nogi were practiced so sparsely they were almost a waste of time. Almost all schools also don't practice defending against punches or if they do, it's once again so infrequent or unrealistic that it's also a waste of time.
In my experience, a vast majority of bjj guys have a negligent amount of experience on their feet, even in a grappling context. Couple this with a sport culture that encourages pulling guard and you are giving the puncher the best chance possible both on the feet and on the ground.
I have two instructors, both of whom were black belts under separate equally legit, traditional lineages (if lineage means anything to you. This story will tell you it means little).
1. My first instructor tried to steal something from a super market. He was confronted by loss prevention. I heard my instructor went for a heel hook and got his ass beat by loss prevention guy. Let us assume that loss prevention guy has no experience or at least isn't a black belt. My instructor is a small dude - about 135lbs when I saw him last. He was supposedly a judo brown belt but I never saw him stand up once.
2. My former instructor was apparently "challenged" by a coworker to "hold him down" after discovering he was a black belt. Let's assume the challenger has some wrestling/grappling experience but is also not a black belt. This black belt isn't very good, his stand up is atrocious, and his cardio is garbage. My instructor could not take him down, apparently pulled guard, and went for an armbar. At some point they agree to stop the match but I forget why. My instructor's head looked like it had a leopard pattern - big bruises everywhere - and his elbows were skinned pretty good.
One interesting fact about both instances is that both instructors were self defense instructors. Neither person was prepared for how someone acts outside of a simulated, grappling context.