Yes, keep them for sure. I personally think that most are done wrong. But when a creator does it right, such as with PMV's having the right kind of music, coupled with fast switching to only those juicy bits that don't divert, but rather retain and amplify the continuity of the experience, can make for a unique and wild ride... The quality problem arises because of those continuity issues, and by poorly chosen combinations on the part of lazy editors; but that should not be the cause of that whole category of videos being removed. Somebody just got's to raise the bar.