Again this just boils down to definitions. Different people have different definitions for terminology as this thread shows. 

For proper and reasonable debate on a topic we must agree to the definition of terminology first. Then we can discuss the topic and its downstream effects with integrity. 

I use gut feel and instinct interchangeably and per definitions this is correct. Your idea about gut feel is not correct per definitions. What you’re referring to is wisdom or experience. 

Dictionary definitions: 

Gut feel: noun. an instinctive feeling, as opposed to an opinion based on facts.

Gut feel: noun: a strong belief about someone or something that cannot completely be explained and does not have to be decided by reasoning

Instinct: noun: the way people or animals naturally react or behave, without having to think or learn about it. 

Instinct: noun: an inborn impulse or motivation to action typically performed in response to specific external stimuli.

Per these definitions they’re closely related if not interchangeable. 

 An instinct is something I can react physically to without my brain having to help consciously.

But judging character takes experience and experience comes with time.

Raw instinct without knowledge could have detrimental effects.