There are a lot of people who don't like Usopp lol, it's not just Nami/Lunami fans.
There are those who are extremely apologetic about him, constantly defending his repetitive cowardice because he's supposed to be the "relatable guy", and they also love telling us to wait for Elbaf. There are those who are bored of him (like me) because he hasn't been interesting in a while thanks to Oda's negligence. And then there are those who straight-up hate him for who he is, and they're definitely not limited to Nami fans.
Nami getting multiple great moments in WCI and a significant moment in Onigashima too, along with a long built-up power-up in Zeus, is much better than Usopp has gotten in over half a decade. Oda definitely isn't negligent with her like he is with Usopp.