Because OCF is a joke 1v1 tournament? How much shit is banned due to terrible balance decisions and crippling bugs? You can't use data with so many ridiculous variables up in the air.
Leigs constantly fire from relative safety and suppress/pin infantry way too easily. Every OKW player makes 2 of them, and they are a constant and major threat.
I've been playing OKW recently, and I just sit them next to a truck and let them AFK-fire laser guided bombs that lets me win nearly every engagement. Get vision with Volks -> let leigs suppress -> charge with sturms. It's obnoxious and easy.
Plus you have to take into consideration barely anyone is using Brits in OCF. Can't use Vickers mg, can't use croc, have to worry about gliders hiting an unseen OKW structure causing you a boot from the tourney. I would have postponed the tournament until after the hotfix and given it a couple days to reevaluate the ban list.