It's basic psychology. We all seek out proof we're right, because we don't want to:
1. Be/seem wrong
2. Reevaluate things we believe we know
You're just doing what people do - looking for affirmation that your beliefs are valid.
Now, the bigger question is is that a good thing. It's easy and comforting to live in an echo chamber. It's also what puts Trump as the presidential candidate, makes people dispute the efficacy of vaccinations, and disbelieve global warming.
It's good to hear other viewpoints, and to actively consider them. That's why the Democrats haven't effectively answered the challenge of Trump. They don't sit and think why people would vote for him, and where those people get their opinions from, so they can't talk to those people effectively.
It's easy to caricature people. Don't become one yourself. Rather than reading the comments, read the article, then find something that takes the opposing view. If you're in the UK, think of this as getting The Guardian and The Telegraph. I'm not entirely sure what the US analogous version would be, but I'm sure you get the drift.
Come to your own conclusions. You might still be wrong, but at least you'll be informed and wrong.