Any reason? I just wondering....
If you self-publish, you are responsible for everything, which means you either do it yourself or you pay someone to do it. That means editing, formatting/layout, cover art, printing, promoting, selling. Even if you go e-pub, that just means you aren't printing it.
Whereas even a small press will do most of that for you.
Now, this is taken with a grain of salt because even the Big Five traditional publishers now expect authors to be responsible for a good portion of their promotion. Gone are the days where you just crank it out and someone else handles all the other steps. But that is a world and a half from self-pub.
I'd much rather let someone else take care of all that other stuff, so I can focus on the writing part.