I think it has far more to do with budget than skill because it's clear they packed in as much as they could into the game while making tournament and casual players happy. It's unfortunate that you are saddened with the stages, and I know that others are too... but if you wait and spectate DOA6 at CEO; I think it's going to prove a lot of people wrong.
That DOA is truly about the fun gameplay, and DOA6 does have that. At the end of the day, it's not Horizon or an opened world game. I really loved the backdrops and detail to stages Itagaki AD and will miss them, but overall I am pleased with the stages in DOA6. I've seen some awesome looking matches already and I expect to have many of my own.
I wasn't a big fan of the beta, but it proved to me that DOA can still be a lot of fun even with limited characters and the worst stage in the game.