That's true, if you're confident of posting about different spheres of life, why don't you go for it. As said in the post, there are two types of bloggers
General and specialty bloggers, Although i think that for the struggling blogger, having a niche is the best way to go.
RE: As A Minnow, This Is What You Need To Be Doing To Hit The Bull's-eye On Determining A Niche For Your Steemit Blog.