Casemiro has nothing to do in that list. Modric is looking okay, has a unique skillset in the engine room and levels Xavi (IMO). On top of that, he was aquired on the cheap.
Bale is an unbelievable athlet who gets people off their seats. He dominated the Premier-League on his own, looked decent without his man ban and was an instant success, not only counting the Champions-League trophy but he tore Barca a new one. From my understanding, the Welsh Wizard has got a huge global fanbase and comes across quite nicely in his interviews.
Kane doesn't have any of that. He's a wonderful scorer of goals, but not the impossible ones Suarez did nor does he bring much excitement onto the pitch. Moreover he comes across dull as af in his interviews, his mouth is constantly open and he doesn't bring a huge fanbase to the table.
Di Maria was sold because of similar problems, as were Ozil or Higuain, IMO. You either are playing absolutely brilliant for years or you look very very good. Of course playing well edges it. Tbf, i didn't take all things into my first case, but the aformentioned ones are the ones i think are important.
You really think a lot of fans would want to buy a tricot flocked with Harry Kane on it in Madrid? I say it again, for me he doesn't have the x-factor nor the looks. For 150 mil. or more, you want in an attacker the hype the likes of Pogba or Neymar attract, especially at Real Madrid.