Why do people still believe in the Holocaust?

Can someone please explain to me why everyone's expected to agree with the official story about 6 million Jews being killed under the Third Reich?  I mean, in many countries, it's criminal to even *question* the idea that something might be wrong with that claim.  And you basically get blacklisted everywhere for doubting it, being labled as a denier.

I've done some research on this, and there's actually a pretty solid case that there was no so-called "Holocaust".  One that I agree with, in fact.  Here's an example of an excellent debunking:

http://www.ihr.org/books/rassinier/debunking.shtml

So, with a case that solid, why is it such a big deal?  Why do people believe that there was a Holocaust?

In Nazi Germany, you couldn't say too many nice things about Jews, or else.
In Western Europe today, you can't say too many nice things about Nazis, or else.

I see a pattern here.

The most intense hatred is often found between peoples that cannot live with just how similar they are.
- Christian nutbags hate Moslems. Moslem nutbags hate Christians.
- Jewish nutbags hate Moslems. Moslem nutbags hate Jews.
- Commies and Nazis hate each other.
- Nazis hate Jews.
...etc...

The Communist regimes, when teaching their school children, couldn't go into much detail about why the Nazi regime was so bad (censorship, Hitlerjugend, thought police, kz camps etc), without also describing themselves (censorship, Komsomol, thought police, gulags, etc). So they had to resort to superficial differences (swastikas, rune-lookalike logos, choleric-sounding speeches, etc).

The Jewish scriptures (Torah, Talmud, etc) have this nasty tendency to forbid intermarriage. Do not pollute thy pure Hebrew blood, or else.
The Third Reich had similar laws some 2-3 millennia later.
In fact, the 3rd Reich was actually the last ones on that "genetic hygiene"-bandwagon. It was just the fashionable thing to do at that time.