Because this game is still amazing! Probably even more than before...and why? I'll tell you why!
I got used to modern military shooters like CoD and completely forgot about how great a game can be when it doesn't take itself so seriously. I imagine the feeling I got from playing Halo is comparable, at least, to Saints Row: The Third because this game isn't about camping and getting kill streaks, and staying alive isn't such a big deal either. Halo wants you to run out there and shoot some guys, and guess what happens when you DO shoot those guys? They go flying! And its awesome! I can't believe how much I've missed taking a rocket launcher and shooting it into a group while the announcer yells "Triple Kill"!
Another thing I forgot I loved so much were all the different vehicles you could drive or hijack, which is super satisfying by the way. I took a banshee and racked up a whole bunch of splatter kills but then I got hijacked. No problem though because my friend had a warthog and was waiting for me to hop in the gunner's seat. This brings me to my next point.
It is so nice to be able to talk to people without them being assholes. I usually stick to the trusty party chat, but while playing Halo I forgot to make a party and realized me and my friend weren't having the private conversation we thought we were having. Instead we were being talked to by a woman on our team. And the funny thing is that this became very normal for us. We were joining games that usually had at least one girl in it, which I found to be extremely uncommon in most of my gaming life. Since near every match had a woman in it I had to ask why that was and most of their responses were that they were tired of the piece of shit community CoD has and that they found that Halo's was much more friendly. Playing all night, I realized she was absolutely right. We only had one group who called me a and my friend faggots but we had trash talked our way into a 2v2 private match, which ended in us all becoming friends.
So take what you will from all this. All I know is that I can't wait to play some more Halo tomorrow, and maybe some fellow Giantbombers will give it another shot. Especially if you are tired with everything being so serious in our gosh darn vidya gaymes, and want some good old fashioned multiplayer sillyness.