The Customer is always right.
Another overused, completely ridiculous slogan...
It's just like American Express and their old slogan, "Membership has its privileges..."
or, "That's how it's always been done..."
I've been a member of some very exclusive and not so exclusive clubs in my life. I've normally fount that the members who have always felt a sense of uber-entitlement and quoted idiotic slogans like the ones above usually cause the most problems, offer the fewest solutions and are normally the biggest pain in the ****.
For every time the customer is right, they are wrong at least as often, if not more often. Membership does have its privileges, but that membership also bears a responsibility with it. And things may have always been done a certain way, but that doesn't mean that the process can't be improved upon.
Stories have two sides and we are only hearing one. I am not saying the OP is a negative person, but perhaps they were having a bad day. Maybe the guide was having a bad day. The guide was most definitely out of line if he called a potential customer "negative", as it is his/her job to sell his product regardless of the disposition of his client.
DVC guides have a tough job. They are asking people, who most likely have spent a fortune on the vacation they are currently on, to spend another hefty chunk of change on a DVC membership. Personally, I swallowed pretty hard when I signed all the papers on my first contract.
I guess my point is that no one on an internet forum should jump to a conclusion about how or why Disney hires or fires DVC guides based on only one side of a story.