Obviously, Baldwins, and Skinnies require specific care!
However, personally, I do not believe that it is any more immoral/unethical to breed Baldwins, and/or Skinnies than it is to breed Rex, Teddy, Satin, and/or Long-haired cavies etc! Likewise, I do not believe that it is any more immoral/unethical to breed Baldwins, and/or Skinnies than it is to breed English Lops, British Bulldogs, and/or Persian cats etc!
Again, the argument that Baldwins, and Skinnies would never have occurred/survived in the wild is redundant - Neither would a PE White, Dalmatian/Roan, and/or Long-haired cavy!
Regrettably, it appears that Baldwins, and Skinnies are gaining popularity/ are beginning to be widely bred on a large scale! Therefore, the only thing that we can do, as experienced, and knowledgable cavy carers, is to continue to educate, and to hope that individuals realise that owning one of these breeds is neither easy, or inexpensive!