I can't speak to this. I'm a Go and Python programmer. I learned Go in about ~8 hours and have been very productive with it over the past 2 years.

I've been struggling at work to learn and use Rails for the better part of a year. I constantly have to grab someone and have them help me. Either I'm an idiot, or Rails has a bigger learning curve than people make it out to have because I've never experienced this in all my 10 years of programming professionally.