It was kind of condescending, but I see where he's coming from. Basically, he's saying "a lot of people on Twitter tweet annoyingly. Here are some major offenses that people should avoid."
And the tone probably made it a more effective piece of writing. The putting-off effect of his tone is counteracted by people being more likely to read it because it sounds more extreme/interesting and people's desire to avoid being a "douchebag", which is stronger than their desire not to be "someone who tweets kind of annoyingly."
That said, it was kind of annoying and elitist. But for accomplishing his goal of getting the most people to remedy these poor tweeting habits the most, it was probably more effective than just complaining about annoying ways people tweet.
And the tone probably made it a more effective piece of writing. The putting-off effect of his tone is counteracted by people being more likely to read it because it sounds more extreme/interesting and people's desire to avoid being a "douchebag", which is stronger than their desire not to be "someone who tweets kind of annoyingly."
That said, it was kind of annoying and elitist. But for accomplishing his goal of getting the most people to remedy these poor tweeting habits the most, it was probably more effective than just complaining about annoying ways people tweet.