Scientology is not secretive. It's core beliefs are not and even most of its administration is not. The Church also runs somewhat around 800 websites. Did you bother to look at one of them?

Cult is used as a curse word here, to denigrating and ridicule people who chose a minority religion and helping others as their way of life. Scientifically, Scientology has been tested and investigated for years b y a variety of scholars. All of them came to the conclusion that Scientology is a bona-fide religion by sociological standards of the 21st Century.

I don't think "the Scientologists" will answer here. But I do. What makes a "cult". Well, aside from the formal decision a "cult" would be a group which is secretive and closed from view. Scientology is the exact opposite. The main Scientology beliefs are not only open available for everyone but also made available in dozens of languages and thousands of Scientology organizations all over the world. Most buildings have a library and and increasing number of Churches of Scientology host their own exhibition. Scientologists are usually open to all kinds of questions (except of those "questions" are rather personal attacks) and love to communicate. After all open communication is one of the core principles of Scientology. Here is more about that: http://scientologymyths.info