Maybe it’s the higher Indy that is better for young strong legs (like Ben says) because there’s more energy needed to pop the tail, but the thunders are easier (take less effort).
The energy thing is weird. It's different energy. Yes, a lower truck has a tail that hits sooner, and it takes less energy to make the tail contact the ground, but IMHO, that does not equal "pop." I'll go to an extreme to illuminate the point. Take a deck with no trucks, and put it on the carpet. Yes, you can "ollie" it, but it's really really hard, and you don't get much height, and you have to really to put a ton of force (energy) to get any kind of vertical lift. Now take a deck with trucks, and a super short tail (like 5" tail). The tail will hit much, much later, and will take more force to hit the ground, but it will also be a lot easier to "ollie" because you can get lift easier. Again, these are extremes, and everyone's "sweet spot" between lift, and how soon tail hits, is different. That said, I don't think a lower truck automatically means "less effort" to get in the air. Less effort to make the tail hit, absolutely, but there is a lot more an ideal pop than just making contact.