Why are so many Parker dogs timid?

I like a man-shy skiddish dog. It has nothing to do with their hunting drive and has no bearing on their fear of a bad hog. I like them because no one can steal them or pick them up in the woods but the owner. I had some cur dogs years ago like that and they were great. I bred a cur to a top Parker dog, "Rowdy" and I noticed these were all but one of five a bit man-shy or kennel shy. However, they burned up the woods. I bred same female to a plott hound and got no shy dogs. I have hunted with pure Parkers , around 6-8 and none were shy, but none were boot-licking friendly to strangers either. I think many top hog dog lines tend towards the shy business, and just need some extra attention and handling to get them over it, if that is what you want. There are way too many very happy Parker dog owners out their to make one thing this small quirk matters.