Critical or Negative?

I'm sure every feminist or activist of any sort has heard the line,
"Why do you have to be so negative?"

The word negative said with disdain and a look as if you are the killer of all joy.
That's of course where the term feminist killjoy comes in.

But the question I am posing today is where the line is drawn between being negative and being critical? Does that line even exist at all?

In my experiences I have found that my critical outlook and social justice tirades have been viewed by others as negativity.
"Why do you have to see the bad in everything?"

There seems to be a large scale equation of negativity to any sort of critical thought or analysis. But in my opinion there is a difference between being negative and being critical.

First let's take a look at the definition of these two words:

Critical: using or involving careful judgment about the good and bad parts of something
Negative: (of a person, attitude, or situation) not desirable or optimistic.

Being negative is "criticism" with no reasoning or intent to be constructive. You know those people who hate everything just because they can? Negativity serves no useful purpose, it's mainly an expression of opinion.
Example: I hate that show.

Being critical to me means taking a deeper look at things. Analyzing merits & faults, and recognizing what else needs to be done. So while criticism can appear to be negative, it is not inherently so. Critical thought, especially in relation to issues of social justice, is not only important but necessary. We need to constantly be questioning, analyzing, and looking for ways to make things better and more inclusive.
Example: I really don't like that show because it portrays harmful stereotypes of women of color.

The main difference here is impact. Negativity is negative for its own sake, it ends there. Being critical is pointing out things that are problematic, which is the first step to change.

Negativity is the sign of a pessimist, critical thought is the sign of an activist. (You can also be both!)

So the next time your friend calls you negative for bringing critical thought to the conversation, know that what you have to say is valuable; even if they don't think so.