Reasons For Writing
First off, we don't need a reason to write a song. We just write them and that's reason enough.
Going on a different tack, I listen to the songs posted here and read the OP's posts, but there seems to be something wanting in all of them and that's their creative process, and even their stated reasons for writing what they wrote about.
On their stated reasons, some are quantifying songs to assemble an EP or album as a goal, talk about the technical aspects of it, but scarcely hint at the creativity and the process it guides them with.
Others, also quantifying it by way of writing a song a week (with some even more ambitious than that), also discuss it but leave out the creative process.
Then the majority post their songs for feedback but don't describe the nuts and bolts of their approach and process to creating the songs. I count myself in with this company of writers.
What does it say about the songwriting process? Nothing, but isn't that one of the purposes of this forum.
I'm not saying we should all be obliged to explain our creativity and process for each song we write because that would become kind of over-reaching and odious to some. But, I wouldn't mind explaining what a particular song's process is because it can be unique to each song, to some lesser or greater extent, and perhaps give helpful insight into what drove me to write about stuff that came to mind and how I ended up with a finished song.
For me, when I write a song it's because something is on my mind compelling me to air it out with a song. The mood is set by the topic I need to say something about, which can be a positive thing I want to share, or a negative thing I need to elicit empathy with. That would summon up a major or minor key and I would then find a progression and adjust its pitch to suit my vocal range. Then I'll create the lyrics in conjunction with the chord-melody of the score out of my own abilities to do that at this point in my experience. That's the basic over-view of my succession of steps, but it says nothing about the details each song differs by, where I had rough spots to resolve and how I resolved them. Going forward, I will be a little more detailed about each song I write and post.