Attentive readers were outraged by this phrase from Nanami about Gojo who "never cared about protecting people".
Now let's look through the earlier chapters:
1. Nanami openly states he has faith and trust in Gojo. By Gojo's request alone, he agreed on being a mentor for Yuji Itadori, a teen boy and a Sukuna's vessel officially executed. N.B.: If Jujutsu Society had learnt about Yuji's resurrection, Nanami likely would be in a lot of trouble.
2. Nanami immediately changes plans after learning that Gojo was sealed. Nanami heading towards the very center of thousands of deadly high rank curses, just to save Gojo Satoru (and eventually reaching his own death). Nanami openly states that if Gojo was sealed "it's all over for all humans in this country."
Conclusion: The airport scene was, indeed, just Gojo's imagination. Gojo subconsciously believes that since Nanami "doesn't respect him", this equally means "Gojo doesn't care about people". Which is obviously not the same.