I think this is the biggest factor in Rails' ease of use:
These packages [python] are written by different people, with different terminology, and different styles.
It's like reading a work of fiction (assuming continous, sensible story line) written by multiple authors. They might all get the job done very well on their own, but it just doesn't hold together as well or have the same "flow". Or like when you see a horrible Hollywood flick that has clearly been rewritten and worked over by a committee, losing any strong vision or voice it had.
Then there's the whole personality of the languages and communities using them, but that's a fire I dare not step into...