Why remove characters to begin with. It wont harm the game if there are more characters, everyone has their own favourite, why do they want to prevent us from that.
Because some of the characters shouldn't have fans. How can you like a character that hasn't appeared for over 10-15 years?
Removing characters is fine. Start liking more popular characters instead of the bad ones. Straw Hats, Law, Sabo, major villains, no character past 20 or 30 in the popularity polls should even be in the game. Ace and Whitebeard should be permanently removed and never return. All the large slow characters should be removed for 4. They aren't fun to play as since they're too damn slow.
Edit: Oh god, I just saw your name. Yeah, you're definitely one of those people who like the minor characters.