Scientology is such a weird entity that even its adherents find it strange which is why they fight any exposure. They will go to any length to hide the truth about it, which is really odd considering they want everyone to practice it.
But it's a tax scamming cult of con artists. That's what they are hiding.
Supposedly, the religion tax exemption was okay'd under Clinton because John Travolta was sent to tell the Bent One that they'd go easy on him in the movie (Wag the Dog?) they were making if they got the IRS religion exemption status.