Why are Playlists so limited?

My question is why we still only have this limited number of playlists. Fiesta should be a part of Action Sack (which we still don’t have), how come we need to replace or move other playlists to get a new mode, and why do we only get a new mode every so often?

It’s cool that 343 is adding modes that weren’t possible at all, but why haven’t they added community Forge maps and modes or made their own? The tools are already in the game or already built for them by the community and it seems like it’d be easy to cobble together some crazy stuff for Action Sack or Multi-Team.

I don’t know why they don’t just put them all in instead of having a weekly rotation. Also, I think 9 community breakout maps were put in and 2 new community grifball courts as well.