The choice of location is deliberately insulting. It tells you what spirit infests these persons.
St. Gregory the Great:
"Sacred Scripture itself confirms that sulfur evokes the stench of the flesh, as it speaks of the rain of fire and sulfur poured upon Sodom by the Lord. He had decided to punish Sodom for the crimes of the flesh, and the very type of punishment he chose emphasized the shame of that crime. For sulfur stinks, and fire burns. So it was just that Sodomites, burning with perverse desires arising from the flesh like stench, should perish by fire and sulfur so that through this just punishment they would realize the evil they had committed, led by a perverse desire."
I’m not convinced this is about being insulting however. I think they think they have found a friend in Francis and therefore believe that this was a totally valid and acceptable move.
Plus, complaints against Pope Francis' "homophobia" from a "gay" website: