These are still claims without any context. It mostly depends on how experienced the programmer is. And most importantly, note that one never needs all the functionality from a framework. Typically it's only a very small part, and often the existing functionality in the framework does not match the requirements 100%.
Very often the match is good enough that it pays off to slightly align the requirements instead of patching the framework. The amount by of man-hours poured into the very core parts of rails for example, just processing and dispatching requests, safely decoding the input from a webserver to a useful set of parameters, routing the request to the proper handler and rendering and returning the response is huge. Certainly, you could take something slightly more modular, such as padrino, but that’s still a mind-melting amount of code if you look at all the libraries and dependencies.
You could reimplement most of the basics, but that would be month or years of work and probably still buggy as hell. I’ve seen my share of “oh, we’ll just build our own framework” and they all turned out to be much more complex than the initiatiator expected.
> In the case of some large frameworks it'd be practically impossible to implement what they cover on your own. You simply can't learn the underlying principles and then implement them all in code yourself.
Not even DHH would claim to have been able to build the whole of Rails by himself.
