Why do people focus more on the negative than the positive?

Because the goal we’ve been brought up to achieve is perfection in some way. It might be your appearance, your success, your love life etc. you want nothing but good. When bad happens, you want to fix it. Many feel a need to fix it. Until it is fixed you can’t reach the perfection you subconsciously strive for. I think that’s why people focus on the bad.

It’s instinct. If we only focused on the positive, we’d never be motivated to improve. In other words, we’d stagnate and die.

Human nature, I guess. That is why when people make a mistake, it is amplified but if they do something good, no one notices.

There's a theory. It goes such that condition is only present in people that operate their minds at a rudimentary, instinctive level.

This is something akin to basic animal instinct. As if pain avoidance holds the higher priority for the accumulation of reactive memory in those individuals.

Much the way a puppy will learn to hunker before a rolled up newspaper. Or smaller fish scurry into weed beds to protect themselves from larger predators.

The knee jerk, instinctive reaction is to have a highly focused attention span on things they consider faulty. Also sometimes act as notifiers of same. It's probably also a natural stage in the human maturation proces.

The brain focuses more on negative shit, they have stronger neural pathways or something

People love drama, conflict, controversy, scandal, and so on whether they realize it or will admit it or not...it's just part of our human nature, and that constitutes one of those things on a personal level. For me, I'd be put off by it, perhaps even irritated or angry about it...but I wouldn't focus on it because the compliments of the 20 would have a much greater meaning and impact to me.

Because of self esteem and insecurity issues.
Everyone has something that is a trigger to them.

I think because .. we wish to correct the neg!