Our HBG absolutely display hook shyness. I cringe at the notion that they are a great kids fish, and will readily bite anything. Maybe that's the case however in a larger BOW, and/or with limited fishing pressure, especially if catch and release is not in play.
Essentially, I'm the only angler in our 2/3 acre HBG pond, and it's strictly C&R. Probably fish it 2-3 times a week. Those HBG are very wary, and difficult to catch unless you show them something they haven't seen before, then you will catch 4-5 before they catch on.