canon straight couple: okay they glanced at each other twice before making out/argued with each other and are now in love. seems perfectly reasonable.
canon femslash couple: idk you need more build-up. them being friends and caring about each other and blushing is a bit vague. it came out of nowhere after one of them was willing to die to protect the other. ur ruining their platonic friendship
I'm watching Season 3 of Korra and, YES!, this is exactly how I feel about Korrasami. If Asami had been a guy, everyone would have been able to interpret their relationship as potentially moving toward something more than friendship.
Could it also be interpreted as just friendship? Sure. Many friendships are built on intimacy, closeness, and even a bit of flirtation--all of which can be seen between Korra and Asami.
But so are many relationships.
In fact, relationships can grow out of friendships like that.
Which is exactly what happens with Korrasami.
But, because they were two female characters, it was easy to dismiss the chemistry between them in a way that, if Asami had been a guy, it wouldn't have been.
Admittedly, their relationship was handled with much more subtlety than any of the other relationships running around Team Avatar. But, frankly, most of those relationships--Korra and Mako, Mako and Asami, Korra and Bolin, Bolin and Eska, Bolin and Ginger, Bolin and Opal--seemed over the top and overly dramatic anyway. Most of those were constructed far too fast and were made up of little more than out-of-control attraction and hormones, fizzling out just as fast as they began.
How are they more valid, more easily and readily recognizable as *real* relationships than the one based in solid friendship, connection, and intimacy?
To anyone who thought Korrasami came out of nowhere, go back, re-watch the show, imagine that Asami is a guy as you do, and tell me if you still couldn't see it coming. Because, sure, the girl is subtle, but she's not that subtle.