High profile or not, I would like to hope that many winemakers check this site. I also understand why they probably do not post. That having been said, I would like to encourage them to post since I think that input from folks in the business is helpful to those of us who love, but only consume their product.
Oh, come on!
Maybe we should put up a Scarecrow to keep them away?
Do enough not lurk to filibuster those who do?
This is a Landmark subject… one that I Envy. If it gets off topic, please try to Switchback.
Just Napa?
Just Napa winemakers who sell their mailing lists. 
I applaud their lurking, and occasional input to answer questions from time to time. I also strongly believe that some of the best information about great venues for tastings comes from the folks on this board. I don’t think they follow for any reasons that are any different than the rest. We all share an interest. I hate the notion that somehow some of us seem to pigeon-hole them with this notion that they are producers and they are following this board for marketing reasons. Having met a number of these folks they are just great people, with insights, their own tastes and thoughts… often about wines other than their own. I think they lurk more often than post because there is a risk that their posts will be seen in a different light. There is more risk than reward to some of this. But, I think a lot of these folks have been outside their own universe of wines… and I think their posts about different sorts of wines from other regions are fascinating. Would love to chat with Morgan about Barolo, Mike Smith about wines and varietals he doesn’t make. I think they have a unique perspective and insight to add to the conversation!