Yeah, she is very pragmatic, but you also have to have the vision to do Zara at Dior. You have to be "brave" (or uninspired) enough. If I was a designer I would've never done that at Dior. I would've never imagined Dior to look like that: straight jeans, a white T-shirt, sneakers... That was the core of her RTW in boutiques, and it was orchestrated by her.
Raf wanted to be commercial as well, but his Dior was not successful. It was "merchandised" enough for the time (the fusion sneakers, the Diorama...), but it didn't work. It didn't click with the clients.
And of course Dior is a great platform, but MGC gave women what they wanted during her tenure. And her personality and her input were very important: she had lot of character and a lot of saying (she changed everything, the packaging, the logo, the mannequins, the VM, the materials used at the stores, the looks of the stores...). And they are actually her ideas. Even the way to display the 300€ rings in a wood hand. The design team was also very small if you compare it to Raf's, it was just very few people working directly under her.
And, for instance, Ghesquière at Vuitton has the platform but it's not really as "successful" (yeah, it's another kind of business, but you get what I mean). And Nicolas has his own vision, but IMO he is not a business man. MGC has business very much in mind while working and we have to give that to her. She did what rich and aspiring-to-be-rich women around the world wanted.
The return of the saddle bag was probably one of the best marketing strategies (if not the best) I've seen in my career and it was actually her who decided to bring it back. The monogram as well.
I do think she is a huge part of Dior's success. And, as I said, I believe she's a terrible designer, but it is unfair to say she's not talented as a business woman or, at least, guessing what rich women want. Right now Dior is passé and burnt, and they are having a hard time. I am sure her replacement will be a matter of time, but she's done wonders for the brand business wise.