I agree with your general point (and I upvoted), but I think the author of both of your links misunderstands how even American courts would apply the GPL.

As to the first link:

When a person redistributes a GPLed program or a derivative work of one and refuses to share the source code with their recipients, there is a reason even most American GPL lawsuits are brought by or with delegated authority from a copyright holder of the original work. A regular recipient with no copyright claim might not have as strong of a claim to standing, especially if the defendant claims not to have consented to the GPL in the first place.

Without consent to the GPL, or even if the GPL is breached after valid consent, it’s entirely possible that the consequences imposed by an American court will be damages for copyright infringement and an injunction against further distribution of the infringing work without further copyright holder permission. It is not automatic that source code sharing, which would be an example of what’s called specific performance, will be ordered. It’s only one tool in a court’s toolbox of remedies, and a relatively disfavored one (especially in cases like this where unrelated corporate trade secrets might be exposed by such an order or where conflicting third-party licenses might actually forbid compliance).

The reason some level of source code sharing often results from these lawsuits is not because of a clear legal right to demand that a court order it, but because defendants usually prefer to comply than pay damages and suffer an injunction against further infringement, and plaintiffs in GPL lawsuits usually prefer to forgive past infringements in connection with obtaining compliance.

As to the second link:

The approach of American courts to this circumstance would likely vary by state. The GPLv3 doesn’t actually say that the penalties for the first violation are waived if the violation is cured within 30 days, and the wording for what it does say in this provision isn’t ambiguous, so some American courts would limit their analysis to the “four corners” of the contract/license and not infer a waiver of the penalties for the first violation any more than did that German court.

Other American courts would accept evidence of what the licensor or the license author intended, and therefore possibly waive those penalties in case of a timely cure.

(When I say “some American courts” or “other American courts”, it’s really a matter of which state’s law applies more than which court. But which court is actually making the ruling may literally matter when the relevant point of the relevant state’s law has not been clearly settled by that state’s highest court, when that highest state court is considering reversing its own prior ruling, when it’s unclear which state’s law should apply, or when the court makes mistakes in inexpertly applying the law of a state whose law it doesn’t often apply.)

A lot of people assume that more of the GPL has been authoritatively interpreted in court than is actually true. Most GPL compliance disputes never make it to court, and some that do end in settlements. Only very few end in final rulings, and most of those are lower courts or mid-level courts which in no way (beyond potential persuasive value) bind the rulings of other judges within the state or country.

Disclaimer for this entire comment:

I am not a lawyer in any country and am not giving any specific advice here about how any specific court would rule in any specific case. I have however attended the beginning of US law school including the introductory contracts law course, and have also collaborated in the past with lawyers specialized in the area of free and open source software as part of my Debian developer activities and my director and officer roles in the free software nonprofit Software in the Public Interest (SPI), as well with similarly specialized lawyers when I was in an open source-focused technical role at Google.

To avoid confusion, I hold no current director or officer role with SPI and am currently entirely inactive in Debian, though I officially remain a Debian developer and a non-contributing member of SPI. I also no longer work for Google. I am only speaking for myself here and not for Debian, SPI, or Google. I mention my past work with them only as relevant context informing my comments above.