Yeah that makes a lot of sense. It's why we took a year off from teaching to try to make the definitive version of the deep learning framework we really wanted - and even wrote a peer-reviewed academic paper about the design we came up with.

So today's fastai library really doesn't have the issues that we had a year or two back - it's a really carefully designed piece of software. Amongst other things, we've made sure works with the book, which means it has to last for a long time.