This has been the question on my mind ever since Destiny came out. Why would Bungie feel the need to leave out the core of what made Halo the amazing game that it is? It's sad that you can't get together with your friends and just mess around in a private game. It's also sad that you put in time getting better at PvP but won't ever have the chance to prove yourself in a tournament (Unless you feel like going through the trouble of setting up a "Sweaty"). I'm totally fine with not being rewarded with gear and experience for a private match. Just give us private matches! Sure it's on your "Wish List" but it's time to make it happen :) If we want something, then we're going to keep bringing it up! If you haven't already, go give a bump to these other posts:
https://www.bungie.net/en/Forum/Post/79539853/0/0
https://www.bungie.net/en/Forum/Post/112999381/0/0
And while you're at it, add ranked play!