I TOTALLY don't get the use of the word "justify" so often used in social media contexts?

[quaz]

I guess I need to have it S-P-E-L-L-E-D out for me by someone INTELLIGENT PLEASE !!! No one or two sentence answers will be honored. I'm looking for a detailed and well thought out answer.
Actually I know what it means. I'm only expressing my frustration at people who seem to be preoccupied with being POLITICALLY and Socially correct. The very ones who should read this will totally not get it.

[Zarn]

J-U-S-T-I-F-Y. In text related terms, that means to adjust the block of text. Usually, there are four options - left-aligned, center-aligned, right-aligned, and block-aligned. In HTML / CSS (and so on), it can be a very useful tool to make sure text is presented the way one wants.

If you want a dictionary definition:
jus·ti·fy/ˈjəstəˌfī/
Verb:

Show or prove to be right or reasonable.
Be a good reason for.