[TheDopp]

I just never saw the point of friendlies personally, it's just a waste of a slot for someone who could actually play. Then, people who want to play wind up spectating while someone who just sits there stays in the round.

While not having played PH as much as others, I equate it to boxing heavies on 2fort in a normal game. It's a change of pace temporarily. Except PH isn't as dynamic as a normal round of tf2, so it gets stale more often, which accounts for the friendlies appearing more often.
Also I enjoy heavy in PH, friendly or no. More of a challenge and more satisfying to kill with.