Your first paragraph seems to be entirely nonsense. Almost everyone was first introduced to a high level language. This did not prevent anyone from understanding that those languages are themselves software, written by people. In fact, you generally have to take a whole course on compilers.
Knowing the single fact that a language is ultimately a piece of software is different from having an intrinsic understanding that each high level construct has to be somehow translated to what the computer can do. Everyone learns the fact "compilers provide programming languages" pretty quickly, but beginning programmers don't get early enough into the habit of thinking how what they write in a high level language translates to what the actual computer does, and they end up with broken programs. Whether you are using Haskell or Java, if you don't understand the execution model it's trivially easy to run into problems with memory management, like reallocating memory over and over when growing collections, exploding the stack via inefficient recursions etc. etc.
Yes. Yes, I do. And it makes a tremendous difference.
Abstractions are an absolute necessity without which we could never have built a computer. And may be fine to stay at one level of abstraction for day to day stuff. Knowing the levels below and above however makes it possible to not only use the current one better but to also to navigate the hierarchy and use the best abstraction for a specific task. And design new ones if necessary.
Our CS courses provided exactly this: We looked at single transistors, programmed microchips, implemented a CPU on a FPGA, toyed with kernels and drivers, walked trough the OSI-layers, wrote a compiler, a static code analyzer, used monads and the lambda calculus, learned about turing machines and different computing architecures, abstractions, models and beyond.
Mostly speculation: Successful CS students are by nature inquisitive. They tend to ask the questions "how does this work." They aren't humanoid computers that need every concept spoon fed to them. Semester one doesn't need to teach the stack from high-level languages to quantum mechanics. It needs to get them thinking about basic concepts such as encapsulation, abstraction, and type safety.
