I can't agree with you more regarding following...
"...I am genuine and because write about the things that interest me."
It's impossible to be passionate without being genuine. It would be fake emotion and the readers would feel it.
Regarding niche, I had the same problem at the beginning as I was thinking I should pick just one niche and stick to it. But for me, it would be an unbearable limitation. After all, it's some sort of my personal blog and I don't have just one interest in my life. Therefore, I simply decided to get rid of those niche chains, no matter what some blogger gurus would say about it.
I can also agree with you that just publishing the content no matter how good it might be wouldn't be enough without engagement with your readers and followers, as well as finding and nourishing the new ones.