Failing at Madrid is far away from being average. The style just doesn't suit everyone.
Was Robben a bad player? No, he's killing it at Bayern. Is Khedira a bad player? No, he's killing it at Juventus. Is Özil a bad player? No, he's killing it at Arsenal.
Kroos is forced to play a CDM role, which he can't. He will probably move to some PL club, then wins a championsship as a protagonist.
You guys jump on that bandwagon way to fast, whenever someone is having a bad season, or isn't cutting it at a certain club, many of you suddenly think that he has never actually been a valuable player to begin with because you struggle to seperate form from quality. You need to realize that it often pays off to invest into someone's reject because he might absolutely tear the house down somewhere else. Examples are KDB, Tevez, Lukaku, Salah, Robben (quite some Chelsea here) and so on. That's why some clubs value a player like him high, because they know that he's a good player who is stuck in the wrong environment.