Well not everyone is going to agree on the squat that's for sure....
The thing about squatting is, there are a lot of different ways to do it, and you don't have to be an Olympic-style lifter to get the benefits. There's no doubt that squatting is good for you. There's published research linking human longevity to the practice of squatting for everyday activities. And one of the first things a good trainer will do with a new subject is a squat assessment.
Like someone already said, squatting uses a lot of muscles at once and you can vary that by technique. And it uses the muscles that are most important to human locomotion, and staying upright as one gets older.
I see the trainers at my gym (who all have at least a BS in kinesiology) working with older people every day, and they all work some type of squat with lighter weights into the routine. Mostly a goblet squat with a light kettle bell.
