How were you worse than Sedom?
Radak #1: They did not switch their gods. You switched your honor for something that does not help!
Radak #2: Perhaps also your deeds were worse [than Sedom's].
Malbim: Sedom did not deserve a punishment for idolatry, for they did not receive a Divine creed. They did not have the fundamentals of Emunah 1 . "Asher Chalak Hashem Elokecha Osam l'Chol ha'Amim (Devarim 4:19) ? they are under the Ma'arachah of Shamayim. They should not be punished for idolatry or Mitzvos Bein Adam la'Makom 2 .
Sedom was settled after the dispersion (Migdal Bavel), and destroyed 51 years later. No'ach was alive for the first 10 years, and his son Shem was king in Yerushalayim nearby. They could have received the fundamentals of Emunah if they wanted to! (PF)
Bnei Noach are Chayav Misah for idolatry, blasphemy and Ever Min ha'Chai, and they are Chayav Misah for these! He is Chayav Misah [for murder] even b'Shogeg (Makos 9a, according to Rashi)! Perhaps one who never received basics of Emunah is closer to Ones. (PF)
