Those who fail either don't get a job or are first out the door when cutbacks hit. Science has been particularly badly hit. Undergraduates have first to pass an exam on the works of Karimov before being allowed to defend their dissertation or sit their other exams. A paper fails unless it contains quotes from Karimov. Officials from the presidency conduct the exams, not academics.
Pluralism is now out of the question in Uzbekistan.
Science is especially persecuted and resembles more and more the one-sided, conservative discipline it became in Soviet times.