You ain't allowed to run a ranked server that restricts the way you play the game so your score is artificially inflated. Knife kills are mega hard to get in normal gameplay, hence the awards to get them have low kill limits. Suddenly if its knife and defib only everyone is expert at knife so the rank system is devalued.
Un ranked is fine, you can do whatever you want.
If you come across any of these servers take some screenshots, note down the IP and visit
BFROE (Rules of Engagement) | Bringing Order to Chaos | Home