BTW, this is not a remark, but how do you block a punch if you can't catch a ball?
WS, is this a rhetorical question? I'm not sure if you actually wanted to talk about blocking or ...?
"Blocking" punches, as in karate and tae kwon do-like styles, is highly ineffective anyway. You can cover, smother, and parry, but those "left outside block" type techniques are worthless, IMO.
Nor is actually blocking a punch necessarily a requirement to earn a black belt. Usually, its how many forms you know, and the execution of myriad techniques in the air.
And blocking, or not blocking a punch, doesn't mean a person can or cannot be an effective fighter or take a punch. See: Lamon Brewster. That guy needs every bit of his 10 ozs of leather to even cover his face, let alone throw a 'block.'