I think some people feel less creative if you’re first reaction is saying a character is “like something else” and not really saying something actually about the character. I suppose it really depends on the artist because some care more than others.
I’ll add on to this with another fun fact. waluigi was actually originally going to have a E for evil Luigi on his hat but the original artist died midway through writing the letter. Here is a recreation of what he might have looked like