Cost, accesibility, lack of skills on other instruments, besides guitar.

Having to deal with other musicians who want to make the project there's, and take credit for it, when you did all the writing and singing.

Not having a ton of experience producing or recording.

Being a solo artist, and having to explain the other musicians who played on it, when they are just hired musicians.

other than that...

For a while there I though real band might be a viable option, I just dont know how it would sound for rock and pop music.