The advice is to embrace positivity and you will change yourself fundamentally. Why is it in your mind dishonest to be nice and friendly, and authentic to be angry and maybe cynic? You can get a lot of stuff done and get your way by being friendly, without being in the slightly dishonest or a pushover. Especially when dealing with strangers such as in business or dealing with "authorities". It's the easiest way to get what you need, because people don't want to help somebody who is not friendly.

As for getting mad at stupid people on the internet, you're only getting mad because you expect them to be better. Accept internally that most people on the internet are deranged freaks, or just don't amount to much and the tension disappears and you don't have to be mad. Would you be angry at a cow for being simple minded?