Why is this a thing right now? Please be a bug.
Even though this game is about getting to 50 pts, and grabs/caps being more "crucial" in capture the flag - I've never seen a game sort by grabs. It looks SOOO ugly. Sorting by kills is what every game does, and it makes the scoreboard look more sorted. It just looks like a jumbled mess with grabs.
Secondly, if you're going to sort by something other than kills (if this is indeed intentional) -- Grabs don't mean ANYTHING. Kills mean more than grabs. Grabs can often lead to losing your teams more points than gaining, or just dying as you grab. Sort by caps then, the only measure other than kills of a form of success. Often times its more efficient to NOT grab than to grab, if you're trying to win - making grabs a poor measure.