Why are there so many JavaScript frameworks?

I agree.[0]

I'm not criticizing Javascript nor Brendan Eich but trying to state why Javascript's particular history of minimal built-in capabilities has a ripple effect of motivating lots of bespoke frameworks.

In a similar vein, the early C++ language didn't have a very extensive string manipulation library. So what happens? Different C++ programmers wrote their own little custom string libraries. E.g. Qt QString functions are different from Microsofts MFC CString. Take that example of code diversity and multiply it by 1000x for Javascript.

[0] "The by-design purpose of JavaScript was to make the monkey dance when you moused over it." -- from https://softwareengineering.stackexchange.com/a/221658

For example, a "routing engine" to translate URL's into specific function/method calls doesn't have to be rocket science for smaller applications, yet they are rocket science (thousands of lines of code) in many frameworks. Come up with a standard interface for routing engines and let me choose which implementation best matches our org rather than have to use the thousand+ lines of code version.

You have a choice: bicycle science, car science, and rocket science versions. A large org or special domain may need the rocket science routing engine, that's fine, but don't force all framework users to use the rocket science one. If I use the bicycle-science router, I can read it and fix or customize it quickly.

ORM's, HTML templating engines, field managers (models), can all also be interface-itized this way, and ship with or offer 3 levels: bicycle, car, and rocket.

Frameworks should then only be interface managers, not implemented conglomerates of fat "helpers".

People who spend hours a day working with a flawed tool have incentives to find another. I had that experience myself using BackboneJS day in and day out for over a year. In my own time, I started exploring better alternatives such as AmpersandJS (which was very similar but handled subviews gracefully). After discovering React, I saw a further improvement beyond my then local maxima.

People who lead products and hire engineers have incentives to choose something that will appeal to engineers who are looking for better ways to do things. It can both allow more hiring competitiveness at any given level of salary and filter out candidates who don't care about learning or finding cleaner solutions.

People who create open source software have tremendous incentives to create something new and grow it. Even if it's not actually better than what it replaces, being the author of a popular framework carries tremendous career capital.