Shrug. I don't care whether folks do this. But if you take a mediocre quality article and spin it 50 times, then publish it on 50 websites then you've turned it into crap content by virtue of duplicating it. It's not medium quality. It's crap.
I'm pretty sure it's borne out by the reality as well, spun articles are overall, crap. Yeah, sure, maybe find one counterexample. But spinning, produces crap.
But spinners don't care - it's the volume that matters. Which is fine - I personally have no problems with that business model (it's not mine). Just don't be selling it as a silk purse, I'm not buying that.
Frankly, the more of that crap on the web, the better for me. The higher the density of this kind of crap, the more affiliates in my niche, the more automation, all that forces my site up to the top as being expert. And it's my expert status that I sell in everything, in sales, in link dev, in social media etc. I'm the specialty store beside walmart.