At first I was a little amazed that many negative articles and comments about these companies were being down-voted, just notice the latest article on the status of a pregnant employee at Google, where the discussion's focus was very quickly and conveniently moved from how said employee had been mistreated by Google to how bad it is that Google allows its employees to discuss freely on these topics.
I didn't understand how come these companies have so many fans on this website, but then I realized that some of these users' total comp largely depends on how those companies' shares behave. If I'm not mistaken a FAANG engineer with 10 year of experience has his comp at about 200k in actual salary and the same figure in redeemable shares, so their total comp can approach 4-500k, half of it in shares. As such, it makes perfect sense to downvote everyone that says bad and unpleasant things about your company, because your money actually depends on it. Not sure that there's anything we, the non-FAANG employees, can do about that.
If it matters I've been an user of this website for quite some time, I just wanted to mention that I'm neither powerful nor wealthy.
For example, I often downvote uninformed and highly opinionated financial comments because working inside the industry gives me a different perspective. Also there’s a self selection effect: Those who hate Google probably won’t work there.
Moreover, the less popular a company is, the more they are going to have to pay you. For example in finance Goldman almost always pays below the market rate, because they are the best at what they do and everyone wants to work their. So I think employees of FANG actually have an incentive to spread and promote bad news about the company, to an extent (they don’t want to depress the share price, though).
I see that in certain other topics as well, such as discussions of the 737 as mentioned in the article.
Along with intellectual curiosity, I think it's important to cultivate intellectual humility, and they go together. A lot of what we think we know just by reading the news isn't all that well-founded, so asserting a strongly-held opinion isn't justified. I'm reminded of a cartoon about collecting questions, rather than answers:
http://kiriakakis.net/comics/mused/a-day-at-the-park
So, if you're wondering about downvotes, overconfidence might be a reason, or at least for one downvote.