There's absolutely no difference between console and GUI applications code-wise.
However, in order to create GUI applications, you need to use one library or another. Some like Qt bring an entire framework, including their own string class etc. That doesn't mean you can't use the regular string class from the standard library anymore. Same with the rest of the standard library... there's nothing I can think of that is specific to console applications (not even cin and cout).
So why do people spend time making Console applications, Understandably they're less time consuming and "easier" (if i understood correctly)...but why not put them aside, just get the basic c+ stuff in then hit the books on a library of choice, for example Qt...
The vast majority of software running the internet doesn't have a traditional desktop GUI. It receives only text and outputs only text (HTTP, SMTP, POP, HTML, XML... etc...).
There is far more to the software world than just GUI applications.