I have lots of thoughts about AR and BR for Halo 4 and in general. Its such a tricky thing to get right, regardless of how easy everyone here seems to think it is. Its not as simple as "just spawn with both". Both would have to be pretty balanced with each other and/or matchmaking really tight to ensure you play against the proper skill group. Neither are exactly easy to do. A skilled BR person will usually beat on an AR user, leaving AR user sad. To balance that you either make AR better or BR worse, which leaves BR user angry. Its not as simple as that though, and I believe they could actually balance both to be effective and liked, but its a fine line and would be quite tricky to do. There's also the matter of "adapt" but let's be real here, many people won't do that, and they shouldn't necessarily half to. They bought the game too and should be able to have fun too.
Which leads me back to matchmaking. Hopefully it works well enough and the 2 guns are balanced just enough that together they work out. I'd like matchmaking to still be fast, but to also better match skills. That's not exactly the easiest thing to do either. Hopefully they'll have focused playlists and game types so that it makes matchmaking more effective. I have hopes they'll pull this all off, but I also know its tricky.
It's not tricky. The system was there in Halo 3, and the BR/AR starts would have worked then. If true skill worked, then skilled BR users wouldn't play people who like AR starts. AR start level players will then play people who have to take 7-8 shots to kill with a br. They can certainly kill that user with an AR (since it buys them more time due to missed shots). BR users will get mad because AR has always been the easier weapon to fire. Why make it more powerful? It's low risk low reward, while the BR is a higher risk and higher reward.
As a BR user, it feels more satisfying knowing I out BR'd someone because I had to have great aim, and a good strafe. Is that possible with an AR? Burst fire works at a larger distance, but it still doesn't require much of a strafe or aiming skill. I also find AR starts boring, because at my skill level, having an AR means I have 4 choices. Spend some time looking for a weapon I enjoy using, die to skilled BR users, use the AR (which doesn't have any of the qualities I enjoy in a gunfight), or use the AR/charge/beatdown strategy that everyone uses due to the lunge.
Also, it's laughable to think that because I enjoy competitive gaming, I don't like having fun. Competition is fun for me. Isn't that what True Skill is about in the first place? To match users with similar skill so the best possible competition/fun is ensured? I very much doubt the AR users don't like winning like the competitive players. Otherwise, they wouldn't be complaining about losing to skilled BR players.