I don't see anywhere on here that people don't want vendors on the beach. That is hyperbole. We have to keep it in perspective that it is the Jamaicans who are passing these laws to restrict who doesn't sell and who does sell on the beach and this is not only meant for tourists but locals as well.
Locals don't want outsiders coming in and harassing tourists because that has a negative effect on their pocketbooks. Some here that have been going for decades to Jamaica remember a time when tourists rarely (if ever) were harassed or threatened in anyway. It has mainly become a worse problem with the proliferation of route taxis and robots that make it easy to live elsewhere and come to Negril to "work" the tourists. I believe the only reason that it hasn't gotten completely out of hand is that the locals "police" their numbers making it difficult for them to get a foothold. I further believe that if you open it up to anyone joining the beach scene to sell without some regulation, Negril will become a dangerous place to vacation as well as to live.
Although it is part of the Jamaican culture to become a higgler and colorfully sell and barter with locals as well as tourists, harassing and threatening is not. No one wants to change that culture. That is part of what makes Jamaica; Jamaica. As my departed best friend "Marshall" used to say, "Jamaicans can be very good but, when they are bad, they can be very bad".
Get the "good ones" licensed and regulated so a good standard is maintained going forward. If and when new people want to sell and higgle, make sure they get licensed and live up to that good standard. I don't think that is too much to ask and I think most locals would agree.
Just my opinion.