>>149006388The Waluigi meme started off funny because the whole joke was that Waluigi was a neglected filler character who had earned a level of adoration from the audience entirely because he was particularly entertaining to watch even as he was critically panned.
"Waluigi for Smash" was fun because the idea of Waluigi being butthurt about being just an assist trophy was 100% in character for him.
Then it got lamer and lamer because people started projecting this idea that he's actually a wholesome underdog when the whole reason he was entertaining to begin with was because he's a lovably petty asshat.
He's basically the Jet Jaguar meme gone wrong at this point. People liked Jet Jaguar for "PUNCH PUNCH PUNCH!" when his popularity took off and they like Jet Jaguar for "PUNCH PUNCH PUNCH!" now. Meanwhile, people have started liking Waluigi for their headcanons about him rather than the character we actually see.