Remember, Wikipedia doesn't supply content. Its content comes from a worldwide community of "editors" and as such is as vulnerable as any other social media to personal opinions and other bullshit.
I think they're well past "personal opinions" and far into paid botting and astroturfing. But I agree that it's still useful in places. As is reddit.
Depends on the context.
For STEM, the content there can be exceedingly valuable, and indeed, sometimes the only reliable authority on the topic (e.g. All the cryptography stuff I supplied to Bitcoin Wiki more or less comes from Wikipedia).
For corporations, personalities, and other "entities", the content can indeed be shit - the Bitcointalk page is a perfect example demonstrating this, it was basically a whiner's ranting spot against Theymos until wikipedia admins took down the whole page.