Can I get a official answer from a admin why grifball is on ration and not a normal game type?
I've seen people comment that lameos exploit it for EXP, if that's the case, just make it so it gives little to no EXP.
SWAT has it's own playlist but not grifball? makes no sense.
While the ease of exploitation in the gamemode may have contributed to it's move to a rotational playlist, ultimately the main factor in making playlists rotational is popularity. Grifball was consistently ranked extremely low in the playlist popularity lists that Menke used to post a couple years ago.
What Chimera said.
Swat has some pretty dedicated fans who pretty much only want to play Swat. It's always surprisingly popular to those who don't like it as much.
The rotational playlist logic is instead generally more specialist modes which people are more happy to go back to every once in a while - by concentrating that via the rotation you're making them viable, if only for a week at a time.
One key thing people forget about matchmaking is it isn't about total number of players - it's about how many people are searching for the same thing at the same time.