They advocate socialiaing as pups but feel that rotts are an independent aloof breed (and state that this is what they should be in line with breed standard etc) so there is no reason why people would have their rotts off lead playing with other dogs. Any views on this?
For an entirely different reason that idea is not so far fetched. They have stated that as pups they should be off lead to socialise which is great, then as adults they should be on lead.
When most breeds of dog reach adulthood they loose the interest to meet and greet anyway, and many breeds are just not dog, dogs and are aloof towards people and other dogs, they may have the odd sniff at other dogs, but many breeds prefer to plod along near their owner anyway, so perhaps being on lead would not make much difference to quite a few adult breeds, it is the length of the walk rather than the free running that is important, although a few rounds of retrieve to burn off excess energy still would not go amiss.
My nephews Akita is dog aggressive, he was socialised well as a pup, I didn't help to train him but he went to classes, I can't see where they went wrong with him or if anything could have been done differently,
I don't think it can be healthy to not mix with others to be honest it would make little difference to him, the work was done when he was a pup and adolescent, it just appears that he is very male dominant and can become aggressive towards other males, he is always on a lead now. I would still not put the whole breed of male Akita's in one pigeon hole though, just as I would not Rotti's or any other breed, plenty of teddy bears in all breeds.

But, to be honest many breeds would not suffer from this practice, because they have lost interest in other dogs anyway......... Now, use that consensus on a terrier or gundog and you might have some trouble.