The real reason, the one that isn't BS, is that Sony has the right to control distribution in the region. If they want to require distributors to be licensed with them, that's within their legal right. Lik-Sang obviously wasn't, and not only that, Lik-Sang was in the grey market -- importation of those foreign goods into that region without license. Selling Sony's stuff from another country there wasn't exactly legal. That's why they got sued.
Of course, if you've seen the gamesindustry.biz article, Lik-Sang didn't even show up to court, paid no legal fees and hasn't paid the judgement -- they just closed up shop. It probably IS sour grapes as Sony said, as they did the same thing when Nintendo sued them a few years ago. They tucked tail and ran so they wouldn't be subject to punishment, and then came back later when nobody noticed.