I think there's no point in discussing regulation of a technology, if it can be demonstrated that the technology itself is not worth using in the first place. At any rate, the fact that DRM cannot be secure and hinders sales suggests that any regulation is pointless.
If you note the comment wording (https://secure.commentworks.com/ftc-DRMtechnologies/
), it doesn't specify commenting about regulation of DRM, just DRM in general.
Of course, if you have a different point to make, you should get it into your letter to the FTC