Why does 1.06 default to OFF on OppLocks if it is a desired thing?
Who says Opplocks is a desired thing? Whether or not it should be used is dependent on the application in which the device is being used.
Having it on when it should be off could prevent a multiuser database from functioning correctly, having it off when it could be on, could impair performance when the files will only be used by a single user at a time.
Which of those scenarios would you consider as more desirable?
How would you deal with it if you had both types of files stored on the same device?
Just as an example - a SOHO setup with QuickBooks and Microsoft Office files - would you prefer lower performance or one that just didn't work?