I've heard a few shouts of "hit a grandstand" in pro tournaments over the years, including The Open. Indeed I understand that at the Dubai Desert Classic players have been known in some circumstances to deliberately hit into the vertically faced 'glassed in' hospitality stand/grandstand close to the left of the 18th green hoping to rebound close or get a free drop.
The grandstand and temporary hospitality buildings, indeed, advertising signs and TV towers too, and the allowance of a free drop for 'line of sight' or the provision of a drop-zone, sometimes nearer the green and often on nicely mown grass, has often bemused me.
It's not an architect issue to me though, it's a rules issue.
Perhaps there should be no drop zone/free drop if near grandstands and the like, and if obstructed by one, or advertising boards or TV towers or hospitality stands etc it's tough, the player should have to play the ball as it lies coz they shouldn't have hit it there in the first place.
This example makes me have sympathy with Jean van der Velde on the 18th at Carnoustie, bad thinking and bad shot by him yes, but he didn't aim for the grandstand and got a distinctly unfriendly outcome.
atb