What's wrong with Newscorp owning all of BSkyB?

After left it a day or so, I'd thought now would be a good time to mention Vince Cable and the "Murdoch" nonsense that is sweeping over so many lefties at the moment. First of all, I must say that I don't really understand the visceral Murdoch hating types and the whole "Murdoch == evil => all things owned by Murdoch == evil" equation that goes on in their minds.

Yes, I have seen Goldeneye Tomorrow Never Dies, but I know it's a film, not a documentary.

So anyway, I'm a little confused about why there is so much concern about Murdoch owning the whole of BSkyB and not 39.9% of it. If someone would like to explain what actual difference it will make to what people can choose to watch I'm all ears.

I've heard some suggestions that it will mean that Sky News, for example, will become severely partisan and right wing like Fox News. Fair enough. How though does this effect the fact that BBC News 24, CNN, and others will still exist not just on the Sky platform (which isn't free) but also the Freeview platform?

What's more, what does it actually matter if that did happen? If you don't like it. Don't watch it. Anyhow, I seriously want to understand why it is that Murdoch owning all of BSkyB when he already has effective control over the whole thing, is something that shouldn't happen.