The algorithms you would learn for graphs etc are also just math and equally abstract. What makes the difference in how real you treat the two concepts that are both abstract but generally applicable?
Then you hear students asking, "when am I ever going to use this?"
My good teachers, on the other hand, always tied what we were doing into a larger scheme. If there were similarities or other relations between concepts, they'd be pointed out. If someone wasn't 'getting it', they had other ways of looking at it at hand, would sometimes give alternate methods of doing the same thing, etc.
In short, one tells you to memorize in a vacuum for no good reason. The other helps you learn.
I didn't get calculus. It was a disaster for me.
Now I'm a mathematical epidemiologist. Why? Because someone introduced me to the grander scheme of things.