It is not 4S that caused their profits drop!
It is pretty much due to a consolidation of Android user base under a single brand (Samsung).
I guess they don't have guts to admit that they are failing to compete in their own house.
My @me.com account created a few months ago never worked consistently for me. I often I get error messages when I check email on my iPhone that email cannot be accessed on that account. Can't switch from gmail because of this.