People often do this inadvertently by rationalizing their feelings with arguments that still sneakily appeal to morality or intelligence. In other words, "That feeling of disgust was because you are a good person and/or smart". It works so well because it both feels great, and it can happen when you are 100% in the right.
You've probably obtained some very good opinions via simply feeling put off, and then being correct on closer analysis. But that makes this experience the perfect trojan horse, doesn't it?
It is already VERY appealing to have your negative emotions AND self image validated, and then it feels trustworthy because it has worked out before. Plus, who doesn't want to go ahead and have a strong opinion? They're easier than confusion, and they make you feel like a strong person.
You just have to be really cautious with disgust, and arguments that make you feel great over it. A good mental rule of thumb is this:
If you earnestly know very little about something, or only "know" it through negative viewpoints, that is not much to form a fair perspective. You can have an inclination, but be cautious about cementing an aggressive position, and be open to learning more.
Ideally, you want to earnestly be able to say "I know a lot about [thing], and that's how I formed my opinion". You could STILL be wrong at this point, so it's the LEAST you can do to form a strong position. It's sketchy when the people you disagree with know a lot more than you.
Disgust is incredibly exploitable for sneaking some utter bullshit right through your gates. Please develop methods to check yourself.