Trust me when I say that back in the day some of the more obvious exploits were reported and Blizzard only did something about it rarely, if ever. One had no choice but to learn the jumps, or put someone in position to regrab when the efc was in an unreachable spot just to bait him down. Now that the microscope is on Classic as the definitive World of Warcraft experience, it seems there is more attention being paid to these reports. I doubt they will fix the terrain legitimately (their GY move down etc in later expansions was a total failure imo) but they can react to tickets when people are obviously exploiting.
I do agree that certain spots like top of tunnel and stumps are more about Super Mario skills than anything else. Any class and race can do them.
-GC