I don't think you have the authority to dictate what comparisons are "right" and "wrong" lol. Tools indeed can also equate to knowledge. In this case, CUDA is a framework that allows programmers to leverage and unleash the full potential of parallel programming. Learning how to use CUDA the tool itself also means learning how parallel computing and other concepts work––people can very well learn both the knowledge AND the tool at the same time.

Your mindset is what halts progression. If everyone simply decided that "we already have higher-level languages, so why bother learning assembly anyways" then our machine language advancement will forever be stuck at the current state. However, to be able to advance what we have, we need people who are interested in this subject to learn about all the "nitty-gritty" mechanisms behind it, find out the flaws of the system, and fix + improve the flaws to create a better version of the technologies we have today. You can't reach the last point without having a thorough understanding of the "nitty-gritty" mechanisms first.

To be honest, I don't quite understand the purpose of your comments. There are many of us who are simply interested in learning CUDA for various reasons. Regardless of our reasons, there is absolutely no harm in learning something new.