Speaking at the Motor Valley Fest in Modena on Thursday, Binotto explained some of the thinking behind the decision.
"When taking these decisions it is because we are convinced we've made the right decision, and we are pretty happy," said Binotto. "We close a cycle with Sebastian. It's been six-years that Sebastian has been working in our team.
"I admire Sebastian. I admire him both as a person and as a professional driver. I hold him in great esteem.
"Beyond that, over the last weeks, the world has changed. Not only from an economic point of view but also from a technical and sport point of view. There are challenges ahead and obstacles which are going to be difficult.
"We are laying the foundations for our future, and we want to have a specific perspective. We discussed [this] with Sebastian, and we found out we didn't share the same goals, short or long-term goals."