spobo

He basically says it's dirt cheap to host and operate and that it's one of the best things about it.

At the time of the video their bandwidth costs per month was just 5000$ and one paid programmer.

Aka you don't need millions to run it. So I was a little baffled when I saw his first big campaign to raise money.

Have't tested it yet but it makes a lot of sense.

Redefining a class isn't dependency injection it's a hack to get the compiler to stop complaining. It works but it's very unclear to the person reading the program that a class your code depends on was actually redefined somewhere else.

For testing purposes placing this mock class somewhere at the start of your code is clear but only ever practical in that scenario.

I can also imagine that some programmers might not even think of the possibility that some code they depend on was overridden somewhere else.

In real maintainable code where you want to swap out behaviours it's nice if there was a special way of defining your dependencies. This is the same for all languages.

Deject offers a way so you don't have to fiddle with constructors but instead you have handles in your classes that you can override with different behavior if needed.

TL;DR: Yes, Ruby is powerful and you technically don't need IoC containers. But to make it maintainable for everyone it's a good idea to do so anyway.