Listen. I didn't mean that offensively in any way. If I understand what you're asking about, the pillars at the stadium are much higher strength materials, reinforced in the ground, and need to carry mostly a fixed load. Although you might think the "pillars" on the ship look similar, they're much weaker materials and yet the structure on the ship has to be designed to handle dynamic loading from all directions. For example, as the ship sways the gravity force is changing direction relative to the ship. One is a more civil engineering and the other more mechanical. Engineering problems are usually a trade-off. If you want a true open space in a stadium with no obstructed views, you have to make some sacrifice in some other area, maybe cost, materials, weight, changing the pitch of the roof or something else. On the ship, this kind of trade-off was probably either not worth it or not possible given safety or monetary constraints.