Okay be prepared for one very biased post.
I'm all for pure breeds, because thats the only way to save them. If every one had at least one pure breed in their backyard and bred them to the standard. In my experiance males are hard to get rid of, cross bred or not, and many people dont know the difference, until they decide they want to show them. and suddenly they find they can't, because what they've got is a commercial layer which isn't a recognised breed but a copyrighted hybrid of many breeds, although they can probably be shown in ag shows. I agree there are some pretty cross breds, but when you look across the choices of pure breds available there are some very nice breeds there as well ( I saw a beautiful seabright yesterday). Why get a mongrel if you can get a purebred for the same price. I get annoyed when I talk to people who are after a specific breed and then because they can't get them straght away they go for a cross bred that someone hasn't taken the time to grow out properly. ( ok that was recent event, and I had put alot of work into finding names and pointing out breeders that they could talk to who had the birds, just not on them that day, I felt I had wasted my time) but then thats just me, and its my personal opinion. After all many show breeders also have pen of comercial layers just so they have some eggs to eat when its breeding season.