Its called commercial pressure
de facto
I would have hoped and likely thought that the skipper and FO having had almost two hours to discuss it. Went through actions on seeing the required visual references and actions on one or both being unhappy and if 'you' perceive a little quelle surprise in one or other pilots voices it is likely a joint one of , 'why are we even here in the first place'. Which having flown for 6 hrs and flown two go arounds is not that unreasonable a question!
In any other airline diverting would a) likely not have been necessary as they likely wouldn't have dispatched and b) if they had done so would have been patted on the back by the aboves for taking the decision.
FZ doesn't work like that. NCC send you ACARS messages saying. DO NOT DIVERT, CONTINUE, Chief Pilot says continue, YOU ARE LEGAL TO CONTINUE. NCC will tell you that you will be reported if you don't hold. NCC tell you that you cannot offload passengers who assault crew or are drunk. NCC of course aren't legally responsible as you correctly say the crew had the ability to say no. But in reality they had as much ability to say no as people had not to get in the box cars back in the day.