Twelve reasons to go out, including it is commanded...
http://wol.jw.org/en/wol/d/r1/lp-e/202012205?q=reasons+for+preaching&p=par
What happens if you do not preach? It has organisational implications. You become "inactive". You are no longer "approved". You no longer qualify for "privileges of service".
Check out the Index on "Meeting for Field Service"
http://wol.jw.org/en/wol/d/r1/lp-e/1200273747
Not much of this is available on-line but I bet the list itself shows that there are activities for preaching arranged by the congregation. Indeed there is a "Service Overseer". Tools (publications, carts etc.) are provided. Territories are assigned. Records of activity are kept and used to gauge spirituality.
According to the Shepherd book....
- the responsibility of of the Group Overseer is to take an "active interest in the spirituality of each person in the field service group", "concentrating on those who are weak, irregular in...field activty, ... or inactive", "assists each one in the group to have a regular, meaningful and joyful share in the ministry". p23-24
- signs of spiritual weakness includes neglecting "regular participation in field service (Acts 20:18-21)". p48
- the Service Overseer "motivates others to have a full share", p20
- he also has to arrange the meetings for field service and make sure there is plenty of literature and campaigns are resourced properly. p20-21
- the Congregation Service Committee "assigns publishers to field service groups after consulting with group overseers involved". p22
- a longtime inactive one is "invited to share again in the ministry" only after two elders have determined if he "meets the basic requirements to serve as a publisher", as outlined on pages 79-81 of the Organised book and km 11/00 QB. p52
If you look at the articles associated with all congregations of Jehovah's Witnesses in the UK as charities you will see there is a statement about organising preaching activity.
OK, no one is disfellowshipped for not going on the ministry but we all know that
- it's highly organised
- there is constant pushing to do as much as possible from the platform under the guise of it's a command from God and is reflection of our love for him
- social pressure to conform and do as much as possible
- social exclusion if you are perceived as weak through not doing field service
- loss of status and privileges if field service activity is low
- they might term it personal but that's not the same as independent