I grew up with Wally from the Mark Waid run of Flash 90 onwards (a bit before Zero Hour, when Impulse was introduced). I was puzzled when the Justice League DCAU cartoon made him into a goofball, since he wasn't like that in the comics. I figured they just needed to fill the prerequisites in that League (John Stewart being the minority on the team, Hawkgirl to have more females, Wally to have a young, funny guy since Superman, Batman, Wonder Woman, Jon Jonzz were all sticks in the mud).
But the goofball Wally had more personality than even comic Wally soooo that shorthand was ok. Carried over to Young Justice, where he was also pretty goofy.
When Geoff Johns reintroduced Barry in the comics, his and Wally's personalities were sorta interchangeable. Sorta. Guess that's why they got rid of comics Wally.