I don't know, good job we all have different opinions and things that we like to see, otherwise TV programmes and movies would get very samey and boring. As a huge Dr Who fan myself (of both past and present incarnations), I love seeing the storylines of the Doctor's companions, whether they be male of female. I don't think the so-called mystery girl trope takes away from the Doctor at all, but actually adds to it. Yes, I loved the older Doctors, discovering new planets, it's inhabitants and the various timeliness without as much of a back story as it has been of late, but I have loved learning the mysteries and back stories of the likes of Amy, Clara and Donna. Infact, they have helped show what the Doctor can do, the mysteries he (or she) can solve and ofcourse, Clara's storyline showed that she sacrificed a great deal to help the Doctor! I think the prolonged mysteries keep viewers hooked and interested as to what's going to happen next. Kind of like a book that you can't put down as you need to know what happens at the end. Just my opinion though.