Interesting point. I find I can be pretty okay jumping onto a rails project, as I know a lot of the conventions. Where to look to see how things are connected. Admittedly, it's taken me sometime to learn how a multi architecture go project using thrift is setup :)
I call this "magic" and I dislike it very much. I'm a very explicit person. I like the ability to jump into any project, regardless of language, and be able to figure out how it works. This is typically possible with Python, Node and PHP with most web frameworks. Ruby with Rails? Not at all and for precisely this reason.
I'm fine with abstracting things but only to a degree. If you're doing a laundry list of complex things with a single statement, and I'm referring to web server specific stuff not ASM instructions, then your framework is going to require more ramp-up time than any other explicit one.