Reason why whale meat is red is due to the whale not being bled. They can't bleed the animal because of its inherent size at sea.

The whale white meat is actually more fat (blubber) then meat.

As LapLap mentioned, it was kind of "forced" fed on you as part of a traditional lunch program in public school. Regular Japanese folks feel the international heat over whale killing and many of the younger generation don't feel its cool to eat it at all.