Surely what you state here can be said of any advice given due to experience. As long as the natural inclinations of younger developers push up against said advice, it's completely sane to give it. Because without it, young developers will have an incomplete mental model, and will lack the intellectual tools to potentially make better choices early in their career.
Also it seems to miss the point somewhat: choosing 'boring' technology has little to do with working on things that are unfulfilling. On the contrary, when tech stack choices are the thing from which developers derive their excitement from, in my view, it's often "empty calories" masking the lack of "emotional nutrition" they are getting from the problem they are solving or the users they are serving. For every whiz-bang neural network getting users to click on ads, there's a 'boring' embedded system running on an ancient C framework somewhere putting satellites in space. I'd rather work on the latter any day of the week.
As Hamming said, "if you're not working on the most important problem in your field, why not?"
I gather your response here is meant to be a retort to the idea that you should be working on the most important ideas in your field, or that the question by Hamming implies some sort of judgement if you are not. That's not the point of the question. The point of the question is for you to reflect on the reasons you are not, as a means to helping you guide your future choices insofar as working on things that are important matter to you. (Which for some, may be not important at all.)
Many people do not reflect on the reasons they work on the things they work on, or on the weight they give to the import of the problems they are solving, and so need such a question to be asked to help them to understand their needs, motives, and goals. When I first read the question I was in a situation where yes, I had financial needs that were pre-conditions for a job, but I failed to recognize the degree of choice I had over the problem space or system I was working in with regards to focusing on problems I cared about solving (or, more commonly, avoiding working on problems I considered meaningless or superficial.)
The problem is actually finding jobs where the problem itself (rather than the tech stack) is compelling. Personally, I haven't seen much of that outside of academia or the elite of the elite Google X type roles.
I freelanced for a guy who ran a cabinet factory, helping him integrate his automated fabrication equipment with his customer ordering system. Dead boring old technology, but extremely interesting to me learning about wood-working and stuff.
I don't know if I have a point, but I bet if you're not picky about tech stack (at ALL), you can find some really cool work to do in non-tech industries.
Also it seems to miss the point somewhat: choosing 'boring' technology has little to do with working on things that are unfulfilling. On the contrary, when tech stack choices are the thing from which developers derive their excitement from, in my view, it's often "empty calories" masking the lack of "emotional nutrition" they are getting from the problem they are solving or the users they are serving. For every whiz-bang neural network getting users to click on ads, there's a 'boring' embedded system running on an ancient C framework somewhere putting satellites in space. I'd rather work on the latter any day of the week.
As Hamming said, "if you're not working on the most important problem in your field, why not?"