Same sex marriage was legalized in 2012, the same year Korra premiered. There was no “virtue signaling” in the way it exists today. Being gay-affiliated was a liability still in so many ways. The backlash to same sex marriage legalization was huge at the time. This is before Target sold “Love Wins” rainbow T shirts. Lots of people said the homophobic junk you claim no one says when the show first came out. And I completely agree with you that their romance wasn’t explored enough, but you are underestimating the censorship at the time. The creators snuck it in late so the cis-hets couldn’t censor it. It had to be subtle. I sincerely hope for more actualized bi relationships in the future, but I respect Korra for what it accomplished at the time.