You can make sprites and have decent drawing skills
Sprites look better if you try to make them look as if they actually came from a game, the pixels don't line up and the colors are too weird on these. The backgrounds need work too, and it's not because it's JPEG that it looks bad.
And yeah, sometimes you can't always explain why a joke isn't funny, sometimes it just is.
I recommend looking into improving your art and writing skills. Or hiring an artist and writer :/