they are used primarily so that you don't constantly get
challenged by people who don't want to play, which is particularly annoying while in a conversation."
Huh??
If they cannot get challenged, how the heck do they ever get to play? What conversation?
Just because someone has the Busy Or Do Not Disturb status on DOES NOT mean they are actually either of those things.
It means they do not want to be pestered by lower ranks or people who constantly challenge. You can still challenge people yourself. It is a convienience for the people who have paid to play this game.
So if you are so fed up with waiting to get into a room SUBSCRIBE, it doesn't cost that much and you can get into full rooms. If you don't want to do that then why are you complaining? You have a way to overcome your problem, there is no need of getting rid of things to suit yor needs.