Though you understand the changes and manpower it takes to make a DLC? But, Japan isn't a DLC friendly market like America or Europe is. For example, with the tons of title updates Street Fighter has, Capcom Japan still went with the disc option. From Street Fighter IV to Super Street fighter IV to Super Street Fighter IV: Arcade Edition and finally to Super Street Fighter IV: Arcade Edition ( 2012 version). When AE came out, there was a DLC was that offered half the price but the Disc version came with costumes for the newer characters that came with it. ( and other updates) All that took player testing, months of leaks and guesses but we still play majorly with the versions we have.
Granted that Capcom isn't PD though there are alot of players within the community who still want certain characters and what not.But, You could always tweet KY and make him see a petition but he has to go through an a whole lot probably like Ono-san has.
Shoryuken.com has influenced the changes in Street Fighter IV but it all came down to Capcom. ( I am probably missing some people like S-Kill who use to play for the community also who has helped the demand of change) Overall, everything went to a disc.. and I have all three titles ( SFIV, SSFIV, and SSFIV:AE)
If you guys wanted a new mode in, probably it will come in the next disc.