Hi,
I don't know much about the local directories you are using but I can tell you that something similar happened to me - on .ro -Romania, and I know how irritating it is, and how funny the whole situation ends up when you contact the company and laugh in their faces - for example one particular company offered a client of ours to develop their website - of course they had a website which was actually number 1 on in a very competitive industry - Ohh, I replied to the email they sent - where they offered to both build the company a website and optimize it, and I asked them how come they didn't find the website if they are so good? :)) The company was well known - placed on the first position - so that means, and must mean that the agencies that are trying to steal our clients don't even check to whom they are sending the "templated mail" - this could also mean they are simply buying the contact information from the directory itself - and that the directory sells the e-mail addresses which they promised to keep private.
From my point of view if the directory has no source of income: meaning adds or asking for money in exchange for a listing, they must have some income from somewhere else - just think of all the possibilities...
I think starting exclusive directories to those that " can answer basic SEO questions and have an email address with the same domain as their marketing web site." is an awesome idea - and I would love to help out!