If the only GPLed component used is the Linux kernel, you probably aren't entitled to any noteworthy source code. It's well established that using the kernel doesn't create a GPL requirement userspace software running on the same device, and the most likely arrangement here is a completely-uncustomized kernel paired with an open-source userspace program that does all the interesting bits.
It's trivial in terms that it will cost them nothing, because it's very likely there are no changes to the kernel, or nothing of value nor commercially-sensitive anyway.
It's not trivial in terms of big company bureaucracy - this request will have to go through so many levels of red tape that they (correctly) decided not complying to random people's requests is more profitable.
I'm sure if you actually sue them then they will comply right away, because at that point paying for some engineer's time to tar up the source tree and send it to you now becomes cheaper than lawyer time.
But their analysis is correct in that nobody will waste time/money suing to get what is effectively a stock kernel they can get from the official source anyway. Which is why these complaints are also a bit stupid - they're not asking for anything of value or using the GPL to advance software freedom by freeing up some valuable code, they're just wasting both theirs and others' time asking for something they can already download directly.
> because it's very likely there are no changes to the kernel
That is a gratuitous assumption. My experience is, as long as there is the smallest custom hardware, you will have to make some tweaks here and there.
> they're not asking for anything of value or using the GPL to advance software freedom by freeing up some valuable code, they're just wasting both theirs and others' time asking for something they can already download directly.
I'm sorry that the company which is making lots of money by using a copyrighted SW has to "waste" 200 dollars in some bureaucracy, printing and postage. But is the license of the SW they are using, and should abide by it.
> That is a gratuitous assumption. My experience is, as long as there is the smallest custom hardware, you will have to make some tweaks here and there.
How sure are you small tweaks create a derivative work? In your experience.
No the license does not hold! Fair use exists independently of the GPL license.
Using GPL software does not take away your rights under the law. As much as the angry FSF lawyers want you to believe - I can use any GPL software in any way I choose and have the affirmative defense of fair use for every single claim they throw at me.
Whether I lose or not depends on specific factors of my use - and I'm sorry but one comma isn't going to cut it.
Edit: A single comma will lose 100% of the time to a summary judgement via de minimis. That's just an incredible legal theory you have there and not something you should be spreading.
Edit2: The Beastie Boys famously won via de minimis at summary judgement for a 3 note sample. It matters not whether those 3 notes were GPL notes or not. It matters what the law is.
