do you want to know how stepping on the accelerator makes the car go faster, or do you only care that stepping on the accelerator makes the car go faster? You are seeing the benefit to black box programming, which is a great way to design a system when all the boxes work. Someone has to make the black boxes though and if you want to be that guy/girl then you need to know more about the language than the guy using the box. There are jobs that are good jobs in each style, so its up to you what you want to program. IMO you would be doing yourself a disservice though if you didn't put forth the effort to peel back some of the abstraction QT is giving you eventually.

Do you want to know how stepping on the accelerator makes the car go faster, or do you only care that stepping on the accelerator makes the car go faster? 

You are seeing the benefit to black box programming, which is a great way to design a system when all the boxes work. Someone has to make the black boxes though and if you want to be that guy/girl then you need to know more about the language than the guy using the box. 

There are jobs that are good jobs in each style, so its up to you what you want to program. IMO you would be doing yourself a disservice though if you didn't put forth the effort to peel back some of the abstraction QT is giving you eventually.