While I can understand people preferring the idea that Korra ends up alone, Korrasami didn't bug me any.
Every other route had been taken. Nobody wanted to revisit the relationships with Mako or Bolin.
The only thing they could have done would be to add a new love interest to the already bloating cast.
They could have bumped up Kai's age I guess or given Opal a dick and stuck one of them with Korra instead of opening up even more useless relationships for overexposed secondary characters.
But even if it had been handled with more grace, it still would have detracted from what Korra was meant to do, namely become a fully realized avatar that doesn't embarrass herself every 5 seconds.