Why is Sterling still underrated?

It is rare for a player to move between two top Premier League clubs at his peak – and rarer still that such a switch would be met with such ambivalence. Why is Raheem Sterling's proposed transfer from Manchester City to Chelsea seen this way?

Why is Sterling still underrated?
It is rare for a player to move between two top Premier League clubs at his peak – and rarer still that such a switch would be met with such ambivalence. Why is Raheem Sterling's proposed transfer from Manchester City to Chelsea seen this way?