>You can read code, rewrite the functionality yourself, and sell it, and not be at odds with copyright

Traditional reimplementation often separates the roles of investigation and implementation specifically to avoid assertions of copyright infringement. WINE, for example, does not accept patches from anyone with prior experience in the Windows code base.

By training and generating from the same the LLM, as one necessarily must do as LLMs are built from training, you inherently violate this distinction.

>If you don't want your code to be used as possible inspiration

Inspiration is a human affect. Training an LLM and generating tokens therewith are mechanical processes.

Courts have not yet decided whether LLM data mogrification truly constitutes fair use.

>then you are not actually for open source, and are using the wrong license. The licenses are legal bindings, not moral bindings

It is not for you to decide what rights someone else wishes to attach to code they release. There are many open source licenses for those wishing to grant various sets of rights. Your reference to morality seems more in line with the GPL specifically, as the Free Software Foundation has a moral stance on freedom in computing not necessarily shared by other open source licenses. 'Free Software' is the term taking a moral software stance.

>"Don't use any concept found within this code" would be a license that doesn't really fit with any current copyright law

Yes. That would be a patent.

>and it wouldn't allow any software to exist, except that made in the 70's.

Patents only last 20 years. They have frequently delayed the spread of certain algorithms and data file formats under their restrictions. This has frequently lead to open source, and proprietary for that matter, being forced to invent their own methods to work around the prohibited ones.