Gale couldn't really give him a long list of the reasons why, because yes, this place was shitty. No one was going to argue with that. But the way to deal with shit wasn't to roll in it. After letting the others console and coddle Finnick for a while, Gale took a turn with food delivery.
When he did, he didn't put the food down within easy reach. Instead, he dragged the bedside table well out of arm's length before setting the plate down. Looking at Finnick, he briefly crossed his arms and watched (waited) for a few long moments before going over and kicking the bedframe, just enough to make it jolt a little.