If a particular blob is just a bunch of switch settings, then it's unlikely that it's
copyrightable -- both because there's nothing expressive about it, and because it's required
to achieve a given functionality (there's no other way to set up the card except to send those
particular bytes). Similarly, information provided under an NDA is not protected by copyright
(because information is never protected by copyright, only expression). In this case, there's
no GPL issue.
Most firmware, though, is far more complex than that, and clearly copyrightable, and thus
copyrighted. In this case, there may be a GPL issue.
Any particular blob falls into one or the other of these cases, and *which* case it falls into
is determined entirely by the law, the particular circumstances, and, ultimately, a judge.
The result may or may not be "dishonest", but it is what it is; how we decide to "think of it"
just doesn't matter, unfortunately...