Are there dangers in writing too simply?

Whenever I approach a story, I build it up as I go, meaning, it’s very basic and I skip a lot of steps in the process. For instance, I didn’t develop the scene when the character had to battle between doing what he wants and what is right; instead I made the choice for him and moved on. 

Basically, I skip a lot of essential scenes that might change the story later. I only do them if I absolutely have to, which is often very late in the process… 

I can never understand how most writers are able to write so much. Their concern is having to scale down while mine is scaling up! This leads to a lot of rewrites, naturally, because eventually I’m forced to confront these events and, inexplicably, the event didn’t turn out as I imagined it to be.

It sounds ludicrous because am I not the one making up the story to begin with? How much control do the characters have?

It’s almost impossible to make the necessary changes so late in the process because I’ve grown accustomed to my ideas, they anchor me in the sea of words that is a novel. I’m a slow learner but I cannot escape this fundamental flaw in my writing. I’ve jumped stories so many times because I was unable to understand my problem and in doing so never finishing anything.