Learning how to use a socket wrench does not make you a mechanic qualified to fix a BMW. It only teaches you how to use a socket wrench, one of many tools used by mechanics.
Adobe Photoshop, InDesign, and Illustrator are three essentials tools of the graphic designer. You could learn every menu item and technique those tools have to offer and still not be a graphic designer.
Graphic design is communicating visually. It is not simply using software. To be a graphic designer, one must learn numerous communication techniques. A few of them:
- how to arrange elements on a page
- how to group together like kinds of information
- how to present that information in a way that communicates to the reader with the least effort on their part
- how to make that communication inviting for the reader to absorb
- when a serif and a sans-serif font is an appropriate choice
- when and whether color is appropriate and what colors best convey the message's meaning to the intended audience
- how best to align elements on a page
- how to use contrast and other methods of attracting the eye
- how to avoid dividing the reader's attention too many different ways (that is, when not to try to attract their eye)
- hierarchical arrangement of elements
- how to effectively use line, shape, imagery, and typography to enhance the message.
Having said all that, I will say that it is not that hard to learn the above things. It does take time and practice like any worthwhile endeavor, and it is a profession that takes dedication to learn well, like any profession.
What IS hard is trying to get people to understand that software is just a tool, and therefore learning Photoshop does not turn one into a designer.