One needs to only look at today’s so called claim of ESCR success (one which is well behind similar results in heart patients from ASCR therapies) to understand why embryos are the desired sources for spare parts:

“We have developed for the first time a simple and highly scalable source of human hemangioblasts,” stated Shi-Jiang Lu, Ph.D., Director of Differentiation at ACT and first author of the paper. “These proprietary cells represent a new and distinctly different population of cells that can be differentiated into vascular structures and multiple hematopoietic cell types.

Emphasis mine. The fact is you cannot patent human beings, including their DNA and ‘parts’. But since embryo’s are not yet (and I emphasize ‘yet’) legally considered human beings, their parts and pieces are not covered. The reason ESCR is the haven of snake oil salesmen is the patent rights. But of course, we can change the laws so that no one company can patent human beings at any stage. We can go to court and prove, using the DNA tests now ubiquitous in courts across the land, the human embryo is not part of the mother but a separate human being. The DNA tests are clear on this as in any murder or rape case. And since the courts now recognize these tests as fact, their results cannot be spun.

Anyway, the ASCR therapies have shown similar if not identical results – with the patient’s cells and genes. So why pay these people more? They are proudly claiming their ‘proprietary’ control of this supposed break through. Now they are just going to rake in the money.