Like many others I'd considered doggedness at least a minor virtue, before its true meaning became clear to me.
Having one dog is boring. The dog shows you his new tricks, you praise him, he does it again, you praise, quickly each tire of the game. When there are 4 dogs at home, life is a continuous game of one upmanship. Alpha dog shows you her trick, the next tries unsuccessfully to top it, dog 3 not an Alpha wannabe does just enough to get by. Old Ted, his own pack, no longer cares. From dawn to dusk, except for nap times is a constant game of look at me. I love it.
Charlie (on the right below) is youngest, smallest, Alpha and dogged. She'll spend however long it takes to keep her pack in line. Away from the others she'll spend all day hiding a bone in the couch cushions, checking on it, moving it, all the while believing no one in her pack sees where she hides it, before forgetting where she put it and starting over. In her single mindedness she never understands where Ted got the bone he's chewing on, or where her bone went.
Then it hit me. Doggedness* may simply be the result of having a head too small to hold two ideas simultaneously. The other dogs are larger and are far more mischievous. They have larger heads too.
*I'm talking about MY 10 pound dog, not you or your dog.