There are lots of reasons to self publish a book. Some of them sound better than others. So it’s a good idea to premeditate your response to the question: “Why did you self publish?” Because, rude or not, people will ask and they will judge your answer.
What Not to Say
“I tried to get an agent (or editor) but everyone rejected my book.”
Even if this is true, it makes you sound lame. No one wants to read a book that no one wanted to publish. If you attempted to go through traditional channels, just keep that to yourself and pretend like self publishing is what you wanted all along.
“The publishing industry wouldn’t know a good book if it smacked them in the head.”
Whether or not this statement is true isn’t the point. It makes you look arrogant and delusional. It also makes you sound like a sore loser.
“I don’t want to give royalties to an agent or publisher.”
This just makes you sound money grubbing. People want to support artists who love their art, not ones out to make a quick buck.
“I don’t need an agent, editor, cover artist, [fill in the blank].”
Again, even if this is true, it just makes you sound arrogant. Everybody needs help of some kind to make their book a reality.
“I can sell more and get rich on my own.”
The odds of this happening are infinitesimally small. Around 50% of self-published authors (including those with multiple books released) make less than $500 in royalties per year. So this statement makes you look both delusional and arrogant.
So What Should You Say?
Whatever you say, keep it humble and sincere. Focus on your passion for what you do. Try to get people excited that you’re following your dreams.
Here are some examples:
“Publishing is something that I’ve always wanted to do so I’m making my dream come true.”
“I just want to tell my stories. For me, it’s not about all the bells and whistles of traditional publication.”
“I love writing and I wanted to share my passion with the world.”
Whatever you say, just remember to avoid sounding critical or judgmental towards traditional publishing. It won’t prove any points you have about the industry, but it will make you look petty and arrogant.
Need help with your self-published book? Or need help landing an agent or publisher? I’m a professional developmental editor for both self publishing and traditionally publishing authors. Check out my editing services.
Ellen Brock 
My parents are passed, as have their siblings. There are so many times when I would have liked to ask them something. About their lives and experiences (including tragedies). But their generation never talked about these things. Even when asked.
I think one of the motivations that can be given for self publishing is just to leave something for the children. Writing for them. There are only so many letters you can write on a gravestone.
Any appreciation beyond that limited audience is a bonus. Both my sons write well (in two languages), so I would not get a free pass for self indulgent vanity writing.
“Writing for my children” whilst perhaps not being the major motivation (we all have ego’s), is something that cannot be argued with.