Every team is free to recruit LDS players that plan on missions. Yet most don't. If they do, they encourage the players NOT to go on missions, often threatening to take away their scholarships if they do. Furthermore, there's nothing stopping non-LDS football players from going on other types of "missions" themselves. Yet they don't. There's just no advantage to being away from football and training for two years.
It's a whiney, pathetic excuse used by ignorant crybabies. Nothing more.