unknowntothem:
what happens when you can code properly and you have a pretty good grasp on electronics and eventually find that the processing power of the arduino (even an arduino DUE) is not enough, where do you go from there?
I think there are two separate issues here. Becoming proficient at programming does not require you to abandon the Arduino or to feel that it is somehow inferior. Which leads neatly to the other issue ...
The choice of an Arduino (by which I include a breadboard Atmega328) or another product depends on what you need to do, not your level of proficiency. For example an Arduino Uno or Mega can't do video processing. On the other hand a Raspberry PI is not the easiest thing to use to read switches and drive servos or stepper motors. And neither of them makes a lot of sense IMHO if you want to write and maintain a big system where a cheap PC or laptop would have all the peripherals built in.
The other thing to bear in mind is that microcontroller development needs a different mindset to PC software development where you have to work with an Operating System but have almost unlimited RAM and disk space. And development of web apps probably needs a different mindset from that required to develop "desktop" apps.
...R