This take is almost as condescending as saying that Ruby isn't a serious language.

Ruby arose and became popular because it caters to a niche that was underserved by the competitors of the time (and while I'm no historian, I think Rails had a big role to play in Ruby's popularity).

Ruby is very ergonomic, and so is Rails. Frankly, almost 10 years after moving on from it, ActiveRecord is the yardstick by which I measure the ergonomics of all other ORMs in other languages, but what ergonomic means will vary from domain to domain.

With languages like Ruby and Python, it's very easy to get from nothing to an app that will work generally well enough almost straight away. A lightweight syntax, a lot of implicit functionality, and a flexible type system are all great for that, but in my current niche, I couldn't use it (I currently work with Rust, and the explicit control is a huge selling point, despite the much heavier syntax and more complicated semantics). That doesn't mean Rust was built without the human experience of using it in mind, though, and arguably the opposite's true.