I think its because for Ashley Cole, he was in his prime and beloved by the fans while the other transfers had spend their prime at their respective clubs. No one wanted Cole to move, things didn't work out salary wise, but the fans wanted him to stay.
For Havertz, he didn't quite click at Chelsea as everyone had hoped, so the fans don't see him as a big loss.
But Cech, David Luiz, Giroud, Jorginho, Willian etc, had served their respective clubs well and were looking to move. The fact that they moved to the other club was incidental.
I think its because for Ashley Cole, he was in his prime and beloved by the fans while the other transfers had spend their prime at their respective clubs. No one wanted Cole to move, things didn't work out salary wise, but the fans wanted him to stay.
For Havertz, he didn't quite click at Chelsea as everyone had hoped, so the fans don't see him as a big loss.
But Cech, David Luiz, Giroud, Jorginho, Willian etc, had served their respective clubs well and were looking to move. The fact that they moved to the other club was incidental.