That if you are a corporation that wants to use this tech in your products (devices) you are advised to join Thread Group as soon as possible because you'll be required to do that when you ship stuff anyways. Possibly compelled by court if you resist.
They probably didn't expect interest from singular hobbyists, let alone hobbyists reading what they put out in the most uncharitable fashion. They have some clarifying to do if they decide that they care.
You are ignoring "practice", which in this context means any kind of operational use, including things like research (they also specify "implementation" separately, to explicitly cover development of products).
Practice here is as in "practice medicine", not "practice for tryouts".
> "practice" here probably means use in your business of manufacturing devices
"probably"?
It's a legal document that lists the things you may not do as vaguely and as broad as possible, and lists suing you as the first recourse in their remediation.
It's unwise to err on the side of "allowed" instead of erring on the side of "disallowed".
It's unwise to err on either side. The license doesn't contain phrase "you do not blog about Thread or we'll sue you". Because that's not what they meant, because it's ridiculous.
There's only a singular threat in the license is here: "Failure to maintain active Thread Group membership while shipping Thread technology may result in legal action, including but not limited to licensing fees."
It specifically mentions "specifications" too, and I did quote that bit in a previous comment that you replied to, so I know you read it.
How are we supposed to interpret "Membership in Thread Group is necessary to implement, practice, and ship Thread technology and Thread Group specifications."
You are specifically, in the license, forbidden from implementing, practicing or shipping the SPECIFICATIONS.
You literally cannot transfer any material or content that reveals the specifications.
Their intention for specifications are clearly stated in the earlier part of the document:
Thread Group [...] grants you [...] license [...] to view, download, save, reproduce and use the Specification solely for your own internal purposes
[...] you shall not: 1) loan, rent, lease, sublicense, sell, or permit others to use the Specification; 2) modify, adapt, translate, or otherwise change the Specification in any manner or create any derivative work of the Specification;
[...] copy or reproduce the Specification except for backup or archival purposes in connection with your internal use; or 4) remove any proprietary notices or labels on the Specification.
So yeah, you can't create derivative works from these specifications. Is a blog post about it a derivative work? Who knows. Probably not. Probably what they meant is you just can't create your own Threads 2.0 specification or create unauthorized translation of it (which although restrictive is reasonable because they just don't trust you to not mess things up). They clearly just want to remain the single source of truth for Thread specification on the net, to avoid ecosystem fragmentation and they intend to sustain themselves from licensing fees from commercial device manufacturers.
Even with all their conditions normal rights to citation, critique, parody probably apply.
They probably didn't expect interest from singular hobbyists, let alone hobbyists reading what they put out in the most uncharitable fashion. They have some clarifying to do if they decide that they care.