Crossbred's are not the whole answer but neither are purebred's (each have there place). Depending on what one's goals are. Crossbred bulls can be just as consistent as purebreds but most aren't (it won't happen in one generation but many).. With that being said how many purebred shorthorn, angus, etc. bulls have consistencey (desireable consistencey)? Being consistently inconsistent doesn't count. A consistent bull needs a similiarly consistent cow herd to work.
What is the purpose of stablizing a line of crossbred's, won't this in affect create a purebred line? Unless both breeds compliment each other and yet are similiar enough to each other to create consistencey.
So Brock would you consider Beefmaster's a terminal breed and nothing more? Sure some of them are just terminal but the breed in general is much more than just terminal.
Breed like to like = like offspring, maybe not the first generation but eventually. This should be the same for purebreds and crossbred's alike.
Purity seems to be overrated in cattle, it seems to me you create your own purity by what you choose to put in your own herd. I mean really why worry about the pedigree from a 100 years ago ( it's irrelevant). Worry about the past several generations pedigree and the future ones.