I think it's so popular now because Extra Easy is so easy to adapt to fit around the family and probably the closest thing to having 'ordinary' meals.
Obviously, if you're vegetarian, Green is the best option and if you don't eat pasta or rice, then Red is. I also think sometimes Red is easier for people who take packed lunches to work/college, so you can have cereal and sandwiches in one day.
I'm currently happier on EE, but that might change if my circumstances change, just find what suits you and do that. x