YouTube's move of banning content by the United States conspiracy theorist Alex Jones comes days after Facebook, Apple and Spotify toughened their stand against the radio show host and banned him on their platforms.
Dorsey said in his posts that "we've been awful at explaining our decisions in the past".
Jones is the host of the daily Alex Jones Show podcast and his platform, Infowars - founded in 1999 - producers another five podcasts.
Facebook, Apple, YouTube and Spotify took down over the past week material published by Jones, reflecting more aggressive enforcement of their hate speech policies after rising online backlash and raising pressure on Twitter to do the same.
"As we indicated yesterday, tweets from Alex Jones and InfoWars are not now in violation of our Rules", the company tweeted from the Twitter Safety account.
While the social network has already been the recipient of criticism for choosing not to suspend Jones, Dorsey's last tweet in particular drew additional ire. "We prohibit targeted behavior that harasses, threatens, or uses fear to silence others and take action when they violate our policies". The Infowars YouTube channel was also terminated.
He said he wanted the company to avoid succumbing to outside pressure but instead impartially enforce straightforward principles "regardless of political viewpoints".
Jones' Instagram (owned by Facebook) account is still active, as is his Periscope account, which is owned by Twitter.
Apple removed several Infowars podcasts from iTunes Sunday, claiming they violated its rules against hate speech.
- Jack (@jack) August 8, 2018He wrote that the company has "been bad at explaining our decisions in the past", and said that Twitter would hold Jones "to the same standard we hold to every account" rather than "taking one-off actions to make us feel good in the short term".
Horne, who now works for the Brookings Institution, said the company's error lay in attempting to separate online behavior from offline activity, arguing that Jones's digital communications "encourage followers to harass/harm people offline".
"Accounts like Jones' can often sensationalize issues and spread unsubstantiated rumors, so it's critical journalists document, validate, and refute such information directly so people can form their own opinions", said Dorsey.
Unsurprisingly, Twitter users did not take Dorsey's defense of Jones well.