Does it simply allow someone to post schematics, firmware sources, Gerber files and BOMs with the implied, "Please don't make a bunch of these and sell them as your own design," or is there more to it?
This license might work just as well for that: Creative Commons by attribution/non-commercial/share-alike (v3.0)
People who are "dreaming" threaten the status quo, and thus also threaten people who are frightened of change and progress. I don't know why there's so much scoffing about open source hardware (or open source anything) because it's not like it's going to take away your safe mass-marketed gear or anything.
Those who scoff tend to lack the imagination to do anything along those lines, or lack the confidence to build their skills up to the point where they are capable of doing something interesting, new, and innovative. It's far easier to bust someone's chops for "dreaming" or "being unrealistic" to cover the fact that the naysayer has balls the size of peas (if applicable) than it is to get off of one's ass and do something.
Repel them. Repel them. Induce them to relinquish the spheroid. - Indiana University fans' chant for their perennially bad football team