This is a really important quote in regards to breeding that I think a lot of people miss. Just because you have an individual that grows well/ has good bud, doesnt mean that individual will necessarily pass on those traits. (why people shouldnt just cross elite cuts all the time)
Although I think the underlying principle is true, it also implies that an individual with certain traits that ain't considered ideal (i.e. a proneness for hermaphrodism) can be used for breeding purpusses, because these bad traits are not necessarily inherited by later generations (so basically what Need 4 Seed said).
With that said, I think the question isn't really wheather certain cultivars shouldn't be used for breeding, but rather if breeders/seed producers should thoroughly test their genetics before they put them on the market. Of course they should