See, the issue is that people are acting like popularity is the most important factor. Characters like K. Rool, Inkling and Shantae, who have major roadblocks and some in-game clues against their inclusion, are viewed as frontrunners just because they do well in polls and are on a lot of wishlists. There's nobody saying "It's all suggestions and popularity doesn't matter!".
I dunno about the others, but whenever I use the "It's a suggestion box" line, it's always in response to someone saying "<insert popular character here> is a shoo-in! They're popular!" or "Why isn't <insert popular character here> in!? They're highly wanted, the ballot's a sham!".