[cybarDOTlive]

Yakuza are criminals sure, but it's similar to mafia. They are not murdering randoms, harming the public, they are not giving drugs to children(mostly), there are codes among these kinds of criminal groups that are probably more dignified than government laws. They are entrepreneurs and they realized they make more money with legit businesses than by getting kids on meth. They are just normal men who don't want to pay taxes, essentially.

See; While many Yakuza syndicates, notably the Yamaguchi-gumi, officially forbid their members from engaging in drug trafficking, some other Yakuza syndicates, notably the Dojin-kai, are heavily involved in it.