This license text in the generated code is not about ownership but about safety. Its only purpose is to restrict the use of the generated code to systems that:
- Cannot cause any damage - Cannot hurt anybody
I know this seems an overly cautious restriction, but I've seen enough (near) accidents with industrial installations to owe it to my conscience to insert this notice. No one can of course prevent you from using sections of the generated code as a source of inspiration in any project. But it is fully your responsibility to check its correctness and make sure that it is safe. This is not a formality. You should make sure the C (and other) code is correct, all of it, including e.g. all macros and restrictions on the range of Arduino timers.
Please also be aware that the Arduino boards themselves are mere educational tools, as opposed to certified industrial controls. Controlling installations with damage risks or safety risks should only be done by a software and hardware chain in which each link is qualified and certified. I know this does not always happen (to say the least), and SimPyLC controls may be safer than some real world controls, but nevertheless it is only an educational tool.
What the license DOES NOT MEAN, is that anyone other than yourself can claim copyrights to your code (of course). But if you would remove the license, someone else could be unintentionally mislead to believe that the C code is safe enough for "the real work", which is not the case. So that's why removal is prohibited.
In general the QQuick Licence applies. It is very liberal, except on the point of safety.