Perhaps there would be significant administrative and legal costs involved, due diligence regarding where the mark is used and so forth, that they've determined

Perhaps there would be significant administrative and legal costs involved, due diligence regarding where the mark is used and so forth, that they've determined is significantly more than that of just defending the mark directly this way to avoid dilution to the point of loss of control? Caveat: I'm no copyright expert or otherwise legally experienced, other groups do things differently so perhaps there would be a way.