I agree with you entirely, but I think this is an if-by-whisky.
That is, you justify a yes or no by defining "programming," or assuming a certain context. Or.. you justify yes or no by defining "hard." There can be a lot of insight in an if-by-whisky, but I think the insight is usually in the justifications than the position.
You're implying (I think) an "is it difficult to become a good programmer?" Totally reasonable interpretation, and I think you're right about the answer. To be useful at a profession is, generally, "hard." It takes time and effort and talent, so yes. The author implies an "will students feel/report that programming courses were hard." His answer is "no," or not compared to other subjects."
In some sense it's the same insight. Programming is not unlike everything else. It's hard to be good.
That said, there is a schoolhouse sense of "hard" vs not that's not evenly applied. Math is considered a "hard" subject. Art, generally, isn't. This isn't universally true, but for the most part, no one stresses about their child or student's level of art proficiency. Ministerial advisors aren't pouring over comparative attainment in art and pedagogical research to try and improve it. That does happen at the specialist end, but not broadly like with STEM.
Educations systems treat most people as prospective non specialists in art, that might benefit from some exposure at a young age. No one gets berated because they're painting below a 7th grade level. Meanwhile, STEM is treated as an essential, employable skill that students are expected to be good at.
So... Should some level of programming be a general skill, like writing or math, that most people need? Or, is it a craft that most people don't need at all. I think that's the question. In one sense, I think yes, because programming is such a part of the world. In a more practical sense, I'd say no, because there's not easy places to apply basic programming skills. Doing something useful with math, like balancing the proverbial checkbook, comes up regularly. It doesn't, for programming.