1. The holocaust never happened. The jews were a hologram.While the laws are pretty dumb, it's wrong to thing of them as "laws against having the wrong opinion". They're moreso "laws against denying historical fact, in particular a historical fact which had an awful effect on our country and many other countries". It'd be like if there was a law in America about denying that 9/11 happened, only what happened was literally thousands of times worse than 9/11.
2. Most revisionists just want to re-examine the numbers, but are prohibited from doing so by law. It's not like it's any secret that the Allies, particularly the Soviets, wanted to stick everything they could to the Germans. They used to claim that every camp was a death camp, that they were making furniture and soap out of the bodies of Jews. That they were shrinking their heads. The original claimed death toll at Auschwitz alone used to be 4 million. It's been open knowledge for a few decades now that the soviets doctored many photos they had of the camps. Considering the sheer amount of propaganda that every major nation was putting out at the time, and considering just how much they've gotten wrong about the holocaust already, it's completely reasonable for people to be a bit wary in accepting the number they are often legally obligated to accept.