They may both want to use the MC, but the difference here is that Nox's ultimate plans and goals are still unclear, and exactly how much place the MC has in them is doubtful.
On the other hand, Candrid's goals are obvious. She just wants excitement, and yes, she may use the MC to get it, but it's not like he doesn't get anything out of that.
Candrid wants the MC happy, so that he can make her happy. Nox, on the other hand, does not care about the MC's happiness. Meanwhile, with Candrid's path you get a lot of side benefits, like Helga and Yuula.
Honestly, they may both want to use the MC, but the way they go about it, and the results to the MC are a world apart. Simply saying 'they both want to use him so they both suck' is reductive and close-minded, in my opinion.
On a side note, while I loved the update when viewed from the original BB path, I don't much care for the Katya path into BB. The story just becomes a watered down version of original BB from that point, where you're missing Helga, Yuula, and Mathilda, and don't even see Katya much.