In this context, Uncle Bob's style was compelling, it felt like a breath of fresh air. His opinionated attitude was also compelling. In general, associating a term like 'clean' to your methodology seems to be a good zealot recruitment strategy. 'Pure functions' is similarly brilliant marketing.
That said, a lot of his supposed solutions actually cause problems of their own if you let the pendulum swing too far. It creates its own kind of complexity. Books like these also tend to sort of get their own momentum, if you look back you see a lot of big names praising them. Surely they must be good, right? Well they were. Clean Code made sense when it was published. It's for the most part not good advice today.