Call of Duty is an easy target, so everyone wants to get a punch in. Call of Duty has never tugged at our heartstrings, and Advanced Warfare isn't setting the series bar much higher. But a Call of Duty game giving players an opportunity to pay their respects to a fallen comrade, even if it's placed within this pseudo-futuristic interpretation of America, is interesting. It suggests the storytelling happening in smaller games might be rubbing off.
It's also not the first game to command eyerolls for a contextual action. It was only a few years ago Homefront bizarrely asked players to "press x to hide in mass grave." It's true. That was probably way worse. There's also the "press X to Jason" meme from Heavy Rain. Players could press the X button over and over, prompting the main character to endlessly and awkwardly yell for his lost son.
Call of Duty's design ethos probably explains why "press X to pay respects" even exists. The game's afraid you'll turn around and leave before paying your respects. The player may not want to, but the designers want you to. The big, floating symbol is the carrot. Who can resist pushing it? Anybody would.