Learn how movement works in this game and how it specifically differs from other games and the scrub randomness of what you are doing that works will fade from your thoughts. You'll know for certain why what you are doing works after that.
For example, in Street Fighter you know that fireballs have a long recovery and if someone jumps one you need to block or eat the jump in because you'll never get your AA out in time.
However, in King of Fighters 13 Fireballs move slow, have to travel further and recover more quickly the slower the fireball...if someone jumps a fireball in that game they are begging to eat an AA. Reason for this is you use fireballs to guard a run up since most folks will simply ROLL through a fireball in that game or stuff it with one of their own and drive cancel that into a move to stuff your run up. Only fast moving fireballs have long recoveries in that game and good luck jumping those. They are punish moves and not spammable.
In Injustice projectiles dont Cancel each other out, there is no roll, and they have large recovery and cant cancel into anything other than a meter variant. So in Injustice you know to either block a fireball, jump it, and you know which based on the amount of meter they have and tend to spend.
See what I'm getting at?
The more you learn why people move and what sorts of movement works the most the more you'll understand why people win or lose in this game and the less scrubby or random everything will feel. Its a new fighting system and everyone is having to learn its own strategies of movement from scratch...its just taking longer due to the addition of stage interactibles slowing down the process and changing the options in every match.
You'll get it soon enough and then youll realize it was never random or scrubby.