Every language out there has pros and cons with different set of tradeoffs , you can't point at a language and objectively say X is better than Y.
Ruby has its place and whilst you think Rails is "magic" the internet begs to differ. Of course any framework looks like "magic" if you don't bother digging into implementation details of it. That is the whole point!
The fact that so many successful companies are using rails in production and scaling it, just shows the complete opposite of what you claim: "an extremely resource-intensive web server framework built around assumptions of what web apps were like in 2003."
There has been plenty of times where i wondered how a piece of AR worked and popped over to the Rails github repo and quickly glanced over the details and had no problem understanding it.
You are entitled to your own opinion, but from the outside, it looks like you are just not familiar with ruby.