Why boomershooters doesn't have a plot?

I played Wrath and i can't even finish it because it has no story. I mean it had some notes but that's it. It only tells you to finish levels without an explanation aside from you're the supposed hero. I just started Ultrakill and i finished the 5 levels. There's no plot aside from the short text on the intro? Is there even a cohesive story?or i just picked bad games?