As somebody who plays Pokken competitively, bad marketing and support.
As
>>39623539 says, The game was marketed as if it were a casual arena fighter, like the Naruto games or most Dragon Ball games. Right off the bat; this alienated the FGC who assumed that's what it was. Then when the game came out and no, it's actually a legit fighting game with full unique movelists per character, cancels, just-frames, a height system, that turned off casual pokemon fans, whjo couldn't just button mash and whined about it being "too repetitive" and "not having enough content, why doesn't it have 60 characters like muh naruto games?!"
Compounding this is that it really wasn't marketed that much to begin with: There was a whole year between the initial tease and the first trailer, It barely got any trailers; with many being japan exclusive, and then it finally launched on the WiiU super late into it's life-span, and as a result, barely got any post launch support: The DLC got held back for the switch version, and TPCI was incompetent at supporting the competitive scene, not supporting third party majors and not advertising any events on official Pokemon social media accounts, with even the official TPCI run tournaments only being streamed on a twitch channel seperate from the main pokemon one, etc. I could go on for ages. It was just horribly mismanagaed.
Which is a shame, the audience is there, people WANT a real time pokemon fighting game: The grand finals for Pokken at World-series events often gets more views then the VGCnd TCG finals combined; it's just so few people even know the game exists or isn't barbones casualshit.
From the FGC side, the game is also stupidly well balanced, has a lot of mechanics to reward and encourage adaption and neutral play, etc.
>>39623476At it's core It is a traditional 2d fighter, see above.