Google algorithm changes and the way Google evaluate backlinks

After Google panda & penguin update, we’re experiencing an old rumour that “bad or low quality links harm website ranking”. Although Google‘s direction about low quality links are not clear, I don’t think so or even don’t believe. We can re-read an old post from Google webmaster central blog that covered enough about this topics can be found here:

The core expression of this article is,

“Finally, keep in mind that low-quality links rarely stand the test of time, and may disappear from our link graph relatively quickly. They may even already be being discounted by our algorithms. If you want to make sure Google knows about these links and is valuing them appropriately, feel free to bring them to our attention using either our spam report or our paid links report.”

I think Google can’t penalize us for thus issue weren’t directly involved, what do you think? Finally, Here's an awesome article contained penguin safe back-links methods: