Strictly speaking SOPA won't be able to do anything to prevent piracy, so I don't think it's that (after all, all it does is stop the URL referencing the server of a given website, so deep links would still work and torrents would be completely unaffected).
I think Hanlon's Razor's appropriate; it's simply been conceived in good faith by complete morons. Possibly hijacked by someone or other who wants a bit more control over the internet, but that's just a guess (or possibly just me being paranoid).
The problem is that searching engines would be trimmed, I don't have much trouble finding the stuff I want, but most of people have just a superficial knowledge of media searching, and this bill would screw them and millions of people willing to share media, myself included
I can't believe that it will pass. There is just too much opposition to it. But I suppose there is always the possibility of something this horrid being made into a law by those who are so disconnected with the people they claim to serve...
It's not even that corporations have too much power...It's that they have too much influence in the electoral process. The biggest joke was CFR which eliminated a lot of the balance between smaller groups and the larger ones. Anyway, SOPA won't pass too much outrage. However, in a year another bill will come up with most of the same facets...And that one probably won't pass either. Give it a couple tries and the outrage to relent and we will eventually see it's like made law. There's no stopping it. The Courts will likely toss it after it passes though, but even that doesn't stop the legislature. Eventually parts of it will pass and stick.