A cult is a religious group that centers power around one individual. I have never heard of one person controlling Scientology.
Obviously, you've never heard of L. Ron Hubbard or David Miscavige.
Cults are generally hard to leave, being reinforced by fear. To keep control of the believers the Cults are generally grouped in one area or have several groups in many areas. Scientology has world wide followers who can choose to stop believing in Scientology when ever they choose... that is not a cult.
Except for the fact that Scientology can sue you, can seek to ruin you, file frivolous and malicious lawsuits against you... Don't believe me?
"In 1976, the Church was found legally liable for the malicious prosecution of an ex-Scientologist named L. Gene Allard who left Scientology in 1969 and was then charged with grand theft."
"In Operation Freakout, the Church of Scientology attempted to eliminate journalist and writer Paulette Cooper via having her imprisoned, killing her or pushing her to commit suicide, or having her committed to a mental institution as revenge for her publication in 1971 of a highly critical book, The Scandal of Scientology."
"In a long and contentious trial, Lawrence Wollersheim, a former Scientologist, alleged that he had been harassed and his business nearly destroyed as a result of "fair game" measures. During appeals, the Church again claimed "Fair Game" was a "core practice" of Scientology and was thus constitutionally protected "religious expression"."
"In the March 11-16, 1981, Danish court case of Jakob Anderson vs The Church Of Scientology of Denmark, ex-Guardian's Office operative Vibeke Dammon testified that the Church did in fact practice Fair Game and had done so in Anderson's case, in an attempt to get Anderson committed to a psychiatric hospital."
That's from 30 seconds of skimming on the Court cases involving "Fair Game"
wiki page. Do some research; for many, it's far harder to leave Scientology than it is to join. They take your money, they force you to write potentially damaging confessions of sins. They can cut you off from your family and friends. Sea Org in the 70s could demand that you have abortions, because Sea Org persons were not permitted to have children...
It's a cult, and there are many countries worldwide that denounce them as such.