I don't want see meat mass produced in this manner. But if WOOL would be produced this way - that would be a lower risk way develop an industry and gain experience of what kind of diseases might result from such unusual factory conditions.
I hope the days are not too far off now, that use of non-biodegradable materials are taxed or otherwise limited enough to avoid them accumulating and potentially harming our environment, which has not included such materials over evolutionary epochs of natural development.
My major concern with sheep farming is that it is done at an intensity which keeps their ranges quite barren of flora. Tree and bush saplings and many native plants cant withstand grazing levels so ranges which could reforest and be more fertile wild or semi-wild habitats, end up tundra-like despite having much more potential for diversity, conservation or sustainable productivity.