Sounds similar to religions. If a religious group sticks strongly to its religion's founding principles and teachings, it's "fundamentalist" and is basically a cult or something like The Handmaid's Tale. The groups that water everything down and are hypocritical and inconsistent are much more successful long-term, with far more members and lots of money.
The main difference is that unlike Marxism, most traditional religions can be the basis of a long-term successful society even if you apply their ideas consistently.