This is a good topic for discussion. The problem with the majority of the grey market films is that they are 16mm which offers much less detail than a 35mm print. On a commercial DVD the difference would be readily apparent.

Although there have been many advances in technology, restoration is still a time consuming and very expensive process which has its limits. While tears, cue marks and dirt can be fixed, the underlying image can only be improved so much. You can't add detail that's not there to begin with. At about $100,000 to restore a single B&W film, the costs to restore an entire series can be enormous. For example, Fox reportedly spent over $2 million restoring the Chans. They would have sell a lot of units to recoup those costs much less make a profit.

Restoration of the print also assumes that it isn't brittle or warped. Monogram was a budget studio and didn't have high production values. Even when brand new, their prints probably were a notch or two below the majors in terms of quality. Add in 50+ years of poor preservation at the hands of the various owners and you can get a sense of the challenges that Warners faces.