Some people, myself included, run multiple sites from one Homestead instance. As the number of sites grow so do the databases and if your Homestead Vagrant box ever gets destroyed you will lose all your databases. This issue is most annoying when you have databases that are for apps without migration and seeds.
Jacob Graf has a quick tip on running mysqldump from within Homestead to automatically back these up. The process is still manual and I think it would be nice to move this to a cron job on the VM so it just happens automatically.