hip stretch in serve vs reverse pivoting in golf?

[TENNIS_99]

I am not sure this has been discussed, but this has been something confusing me for sometime.

During serve, I heard a lot about hip stretching,loading weight in the front foot at the trophy positions. In golf, there is a similarity called reverse pivoting, which means that at the backswing you load you weight toward the front leg and when you swing along you naturally bring your weight back to the backfoot which results in power lose. Reverse pivoting is a no-no in golf. Actually I saw some tennis players do this when they serve, usually I notice their front side collapse when the racquet hit the ball and don't land inside the court which just like reverse pivoting in golf.

So my question is golf swing and tennis swing/serve should be very similar in the nature of tranfering power, why one is a no-no and the other is a must?

By the way, I just observe my own serve that I did load maybe 70 (or less) pecent of my weight to my front foot at trophy position without knowing it. But when I try to load more, my serve collapes. I feel the stability of my lower body is a key to the success of my serve and loading too much weight to one side seems cause problem for me, comments?