WHY?
Modric is absolutely world class. Ask anyone in Spain, whether Kroos can compare to Modric.
Modric is an midfield boss, while Kroos is like Juan Mata. Excellent in his passing and set piece delivery, while being invisible defensively. Both lack physicality in the midfield and if you think Yaya toure slags off, watch Toni Kroos play, because he has been like that since he was young. The other problem with Kroos is going against a team like the Spurs that press the hell out of you. His dribbling is subpar and when pressed, he would concede possession very easiliy (similar to KDB).
When Mata was putting up those stats for Chelsea, I always knew Silva was significantly a better player than Mata regardless of his goal/assist output. Watch David Silva play.
He shields the ball, keeps possession of the ball and retains the ball... Kroos can keep possession, but shield and retain he does not.