Why are you filling out a form?  The group is now at a size where there are a few reasons, many of which are common problems for people running Facebook groups:
 

• We have gotten big enough that people are trying to join to spam us;

• We have people trying to join to get free legal advice;

• Many user names are pseudonyms and if they don't answer the questions it is difficult for me to figure out who they are;

• Recent cases and developments in Facebook rules mean I need to know who is in the group; and

• It takes a long time to go through a list of 14 new member requests, verify their identity, screen shot all their details and save it somewhere.