Also people who have really hot Sound Tips generally don't want to give them away. If you can make a unique sound with some special trick you will have an advantage over your enemies (other musicians).
For instance, the "Blade Runner Blues" patch as I understand it is actually one of the brass presets on the Yamaha CS-80. (Bad recording but here: https://www.firsthomebank.com/personal-banking/deposit-produ...) The CS-80 has a pretty unique architecture for a polyphonic analog. (http://www.cs80.com/tour.html) To get a patch exactly right would require replicating layout, filter architecture and structure, etc.
Knowing basics synthesis, however, can get you pretty close. I have a patch on my Alesis Andromeda (which has some CS-80 type elements such as a ribbon controller, dual resonant filters, and an unfiltered sine that goes to the post-filter mix) that someone did in a user community -- it came out decently good. I was able to Google a book page that gives a good overview of recreating it on other synths. (https://books.google.com/books?id=Jz1JMnZNO88C&pg=PA74&lpg=P...)
Now, to really get the Vangelis Blade Runner type effect, you have to be able to play a synthesizer expressively. This is unfortunately is tougher on most synths compared to the CS-80, due to the CS-80's polyphonic aftertouch that most synths lack. That being said, there are other techniques people could do. I understand that Vangelis used pedals to manipulate filter and volume, and that is something that can be done on many synths that I don't see a lot of people taking advantage of. Don't discount playing technique when it comes to the art of sound design, in other words.
I will say that I think the 'power-law' nature of that is not dissimilar to being a primary sound transduction artist. You don't get a large number of people being celebrities at tutorials, or of disseminating free plugins.
And yeah, I do mean to expand upon this: got a likely domain for it just yesterday. The trick there is that you need to be inter-disciplinary enough that you can produce a really wide range of content, that by definition a newbie couldn't possibly process. I can go from 'slew rates in op-amps in boutique guitar stompboxes' to 'exploiting unusual interpretations of the Circle of Fifths' (did you know the Four Chord Song can be read as a atomically contained minimum-area space in an extended diagram of the circle of fifths?) but a newbie wouldn't cover that range.
There are no secret weapons, just secret masteries: by that, I mean 'stuff that's sensible and obvious, but to the contextless outsider seems like black magic coming out of nowhere'. Any sufficiently deep context seems like magic to someone who has no idea of the scope of that context.