Rule 6: Hate speech, abusive or threatening behaviour is not permitted.

• Hate speech is not permitted. Specifically, speech (broadly defined) which is directed at any:
  • Gender
  • Nationality
  • Religion
  • Race
  • Age
  • Pizza topping preference¹⁾
  • Sexual identity
• In general, it is not permitted to harass, abuse, or threaten people.
• Don't be a jerk.

However, one can hate on systemd all day long here.