Grounding underground cables is not silly. Lightning can strike an underground cable run. The correct installation requires using a ground block at the house even for an underground cable run.
Agreed The OP should reuse the ground block on the house.
All wires can have a current induced into them by nearby lightning
I was referring to grounding the dish/pole itself by running a ground wire to the house ground block.
Without starting a "should you ground" battle ,that has been pounded to death in these forums.
Dish grounding IMO is more for draining the static charge that can build up on a dish, then it is for lightning mitigation.
If there was some kind of fault with the house's grounding system, then it would be possible that it could seek (back feed) the ground through the sat. system to the pole that's planted in the ground.
Although this seems unlikely I have seen it several times