[Someone]

> Just pick Python and move fast, kids. It doesn’t matter how fast your software is if nobody uses it.

The reason nobody uses your software could be that it is too slow. As an example, if you write a video encoder or decoder, using pure Python might work for postage-stamp sized video because today’s hardware is insanely fast, but even, it likely will be easier to get the same speed in a language that’s better suited to the task.

[wiseowise]

Learning that it’s too slow takes users.

[casey2]

They were the users and it was too slow for them so they switched to python. Not C++ of course, what they meant was "the libraries we wrote in C++ were too buggy and slow that using them was slower than if we just used Python."

[Someone]

In some cases, common sense of developers can do that, too.