A question about believability and suspension of disbelief

I have been criticized about my story lacking belief. It wasnt much but I have been thinking aobut my stories last chapter (Vendetta chapter 6) and its lack of believability. I agree, it wasnt very believable. But does that make it bad?

Unbelievable stories some times become a big hit. Look at Batman. 1989 and the begins. they were HUGE hits at the box office, but lets face it. it isnt very believable. What made those unbelievable stories such huge hits.

And superman. My personal favorite but come on. a flying indestructible man. We love him.

I enjoyed writing mine. but, it seems to have been a bomb.