As someone who's worked in marketing, both Greninjafags and Anti-Greninjafags ITT seem to be absolutely retarded.
Greninjafags: Just like Lucario and CHAARIIIIZAAAAAAAAARD have gotten a bunch of merch lines that Greninja hasn't gotten, Greninja has also gotten a bunch of merch than the other 2 haven't gotten, like the bigmore Plushies, the Youkai Parade set amongs many others, like being the only non-Kanto or Alola pokemon to have merch in the Pokemon Centers that opened temporarily. Also a big role in the 1st major Hollywood pokemon movie. It's not a fucking personal thing. If Lucario has gotten more attention recently it's because TPC fuck up everything they do. The Dexcut is a typical way of refocusing merchandising efforts in a franchise that is getting too bloated, saving up other fan favorites to incentivize interest in future title. And that means that the ones currently unaffected by the cut will feature more prominently for obvious reasons.
Anti-Greninjafags: Greninja IS popular no matter how much you cope about it. Sure, it's funny that GF and associates are retarded at managing their moneymakers, but regardless, that doesn't mean he's not getting shilled to positive reception. Ironically the poll will be kept in mind, but for FUTURE consideration by the time future main titles start dropping instead of the year when it won. It's a usual promotion cycle. In one or two years you'll see a lot of Greninja shilling. Then they'll switch to something else, then back again in order to keep interest high. Similar to how Crop Rotation works. It's simple marketing.
In layman's terms, shillmon fucking suck, but they're completely unavoidable. Expect to see a steady rotation of reliable shillmons during the following years, ESPECIALLY now that they have raw interest data at their disposal besides actual merch sales and internet trends.