The problem is when CV has issues and it will have issues at some point usually on a weekend or Holiday - for example the MediaAgent is down or tape drives crap out, no spare scratch tapes in the library etc... = No DB BACKUPS.

If CV is doing TLog backups too then your Log Files autogrow (if enabled) and you could fill up the disk grinding your DB to a halt. Then you have to go shrink all of the TLogs back down to size AFTER you finally get them backed up again. You can point the finger at the backup guys; however, ensuring the recoverability of the DBs are still the responsibility of the DBA...