I am sorry, but I just don't follow you. How does an ad that says "Buy certified Angus beef" damage a breed? Do you mean it somehow damages the animals? or are you saying it damaged the breed registry...the association? if so, then how? And. what industry was damaged by an ad? Cattle ranching? The food industry? And how does this ad campaign damage it?
Angus are as good (and bad) as any other breed of European cattle. You can take a top grading angus carcass and hang it in the same cooler with a top grading Hereford and no one will be able to tell which is which. The same with bottom grades.
But the marketing has created an artificial perception of higher quality which creates a demand for angus bulls. And not just angus, but "black". Black hides sell for higher prices due to "the ad". This means that other breeds have been forced to follow by creating black hides to be competitive. That means infusing black angus genetics into breeds that are historically other colors.
The problem being when a limited number of top performing bulls are used to produce herd sires through artificial insemination... and all of their sisters are being kept as replacements. I'd bet that 80% of black angus animals alive today have at least one bull in their pedigree in common within five generations. It might be 50% that have more than one bull shared in common.
This is why GAR Precision 1680 was so dangerous. He was a top bull with great stats and looked awesome... but his progeny was being used as herd sires and being used on heifers descended from him. The same thing is going on with other top bulls. And those inbred genetics are being carried into any breed striving for black hides in order to compete for dollars at the sale barn.
Curly calf syndrome is not the only anomaly associated with black angus. And other breeds are being damaged by close breeding as well.
Purebred animals and artificial insemination is a great way to spread good genetics and produce excellent animals... but it can lead to trouble, too. When three top bulls are at the top of the pyramid and most bulls beneath them are related to them... and then 80% of all replacement heifers are also related, the genetic potential for anomalies is increased to unacceptable levels. At least unacceptable to me.
THAT is why "the ad" is more than a simple marketing tool. The CBA program is damaging the breed (noted that those involved are trying through genetic testing to catch problems) and why the spread of "black hide marketing" has damaged the industry as a whole.
And just to get it out there, I LIKE black angus cattle as much as any other. I like them enough to criticize those that are playing with fire.