Let's substitute one criminal activity for another. Let's say instead of linking to a site that allows you to download copyrighted material, we were talking about linking to a site that allowed you to order a hit on your wife/husband. Or a site that allowed you to order custom-made child pornography. (1)
I'm pretty sure that, if that were the site in question, many of your rhetorical questions won't seem quite as ridiculous. In fact, I'm pretty sure even the last question you pose, telling a friend the URL, can in some cases be construed as illegal, and certainly immoral. Again, not all cases, but some cases.
And if we forget the slippery slope fallacy and focus on just the linking, how would you feel if a news website actually linked to a site that allows people to download child pornography? Or allows people to order a hit on someone?
1 - I'm not saying copyright infringement is anywhere near the level of wrong I'm talking about. It's just that using something that is clearly considered wrong to all people, is a great way to clear up, in your own mind, whether what you're objecting to is the text of the bill, or the fact that it's talking about copyright infringement. I'm guessing most people here would be all for a law that banned passing out the URL of a site that solicited murders, etc. But when talking about copyright infringement, your preconceived notion that copyright infringement is OK gets in the way.
EDIT: Minor fixes.