Turner is going through all sorts of stuff due to the cable industry being in turmoil so they are trying to find themselves. They do have a couple good shows but it's no Al Jazeera you are correct.
They used to be groundbreaking journalists who revolutionized television news. Then in the late 90s, early 2000s Fox News appeared and they lost tons of viewers to them. I interned with them during this time, and every morning a summary of the previous day's ratings went out on the internal system and every day they were getting creamed by Fox News. So they tried to compete with them and that just led to a race to the bottom. It's sad. Their international channel is 100x better than their domestic, though, because it's a completely different and more educated audience.
I like CNN. They definitely speculate and sensationalize and I yell at them all.the.time. But I do feel informed and I think the coverage is fair. I've been impressed with their treatment of race-related issues and they've been great about Caitlyn Jenner.