Losing is a natural part of the game. People who havent lost havent fought strong enough opponents yet. I didnt lose for my first 65 games on ranked. Then I fought a proper opponent who could probably go 50/50 with me in a room again and again and kinda decimated his/my perfect record.
I suppose you can lose to two things, you can lose to a genuinely good player who managed to outplay you on all accounts, or you can lose to something incredibly stupid, like a tager mashing out 720s two times when you dropped a combo >_>
On both accounts theyre kinda your fault and there is something to kinda learn, whether it be your adaptability (yes, trying to get a read on how often an opponent will dp is amazing), your approach to a specific matchup, or your general skill level with your character. It sucks that the ranked format is only best of 3 rounds because for some people adapting to an opponents style of play takes that long. Losing should not inspire rage but rather facilitate an urge to learn / get better.
My greatest pet peeve in blazblue is a good player... WHO WONT FIGHT OTHER GOOD PLAYERS because they're so averse to losing. Don't be that, and fight those who give you challenges while approaching your mistakes rationally and you'll be a great fighter.