Ola's stuff takes care of backups auto-magically and could easily be made to exclude the system databases. My question is, why even bother? The databases aren't big, take virtually no time to execute the backups for, and such backups are a life saver if you ever need them. Contrary to your thoughts, I do a full backup of the system databases every night and I always keep to active copies of the backups. I think not backing them up nightly takes more effort and has little to offer in terms of ROI.