Citing a source is indicating where the material was originally created, what form it was accessed in and how it was accessed. This usually includes publication information, page number, location on a website, and more. I won't get into the details of citation here. I will admit that my personal citations in my own notes and sources are sloppy. They contain all the essentials, but they don't fit any "correct form." Guess what? I don't care. What I care about are that all the essential information is there-the record, the form in which it was accessed, when and where it was accessed, etc.
At the most crude, citing sources allows me to go back and "doublecheck" what I saw. A citation allows me to as easily as possible find the same source and review it again, making certain I didn't leave anything out.
Knowing the form in which the information was accessed allows me to compare a "new" version of that record or source. Did I access the microfilm the first time? Have better digital copies been taken? Do I need to see the original at the courthouse? Was all that I accessed the first time a transcription made from a bad photocopy of the original record? All that makes a difference, especially when there may be other "forms" of the same record out there.
The publishing I do of information is for my how-to newsletter, Casefile Clues. Do most genealogists publish? No. However, I will say that in the process of cleaning up my citations I virtually always discover something I "overlooked" while preparing every issue. Every time. I'm always adding to my "to-do" list while reviewing my citations.
The reviewing I'm talking about is not the decision of where to place commas, semi-colons, etc. I'm talkin g about gathering all the elements for the citation as some (most) of my older material lacks all the necessary details. It is often when I'm gathering that information that I locate something else that needs followup, or that I notice an error in a transcription I made years ago, etc. Seemingly always something comes up when I clean up the citations.
And that is about me, because it helps my research. I see brick walls I made for myself and information and clues I overlooked.
Citation is essentially about me--making my research better and allowing me to discover more connections, conclusions, etc.
Even if I only did it "for me," the citation and analysis of my sources would still be necessary.
Most successful genealogists, those who "find lots of stuff" cite their sources. They may not have the commas and semi-colons in the right places. They might not even have the commas and semi-colons, but they have all the essential parts to create a citation somewhere.
Thinking about where they got something and how they got it helps them analyze and find more.
Personally if they tell you they "never think about that stuff" they are either lying or have errors in their conclusions just waiting to be discovered.