[Edit - This is, perhaps, an extreme view, and The Sun is in no way alone in using this modus operandi. However, as a Brit I feel an impulsive need to warn those who didn't grow up with The Sun!]
Regardless of whether "everyone does it" (which, again, is not true), it's irrelevant to trying to have higher standards for links from Hacker News.
I agree with what you're saying in general, but if a paper makes stuff up for a living, there's absolutely nothing wrong with discounting what they say until a better source comes along.
The issue isn't that The Sun's readers are "festering idiots," or that the stories are typically unimportant. If that were all, you could be forgiven for reading the article in a vacuum and proceeding from there. No, the issue is that The Sun lies when it's convenient [1], and that whether or not a given claim is an outright fabrication by The Sun's writers is not something you can deduce from the article and the article alone.
[1]: Skimming wikipedia:
"In 1987, The Sun falsely accused homosexual pop musician Elton John of having sexual relationships with rent boys. In another story it accused him of removing the voice boxes of his guard dogs because their barking kept him awake. "
'On 17 November 1989, The Sun headlined a page 2 news story titled “STRAIGHT SEX CANNOT GIVE YOU AIDS – OFFICIAL."'
"On 9 December 2010, The Sun published a front-page story claiming that terrorist group Al-Qaeda had threatened a terrorist attack on Granada Television in Manchester to disrupt the episode of the soap opera Coronation Street to be transmitted live that evening."
http://9to5mac.com/2012/09/03/bruce-willis-dietunes-yippikay...
If those banging on about copyright reform ever need a sign that their message is finally getting though, isn't this it?
No, it's a dead common view. Maybe the very commonest view your could possibly have: "I don't agree with the general policies of X, therefore X is wrong."
Never buy or read The Sun.