Re: PTI internal elections
No one has ever held these party elections in our history through 'open membership" so that tells you why it is a massive risk. People who lose these elections leave the party (mostly because of EGO problems), some will claim rigging and others will give other reasons as it may not be easy to work for a party whose members elected your opponent, it can hurt anyone’s ego.
These elections are way different than other parties. The only party that holds such elections are Jamat e Islami and even they do not hold them through open membership but selected members cast their votes only.
It has huge significance as popular and elected members then award party tickets. Imran Khan cannot sell these tickets or award them to own family members as it is common in Pakistan (or even subcontinent for that matter). It promotes even an average middle class contestant to reach the top level by working hard rather than rich people investing money and then obviously claiming it back with interest once they get elected 