20 years ago, programming was done for limited-memory devices which meant that it was important that the program size was kept small. Today, it's not an important factor as both space and memory are available in abundance.
So, why talk about concise programs? Writing and reading small programs leads to a better understanding of the language it's written in. It shows a language's capability to write small and elegant code. Smaller code usually results in program which runs fast and consist of fewer bugs.
Riot JS is a really tiny client-side MVP framework which promises to include all the building blocks of a website - template engine, router, event library, and claims to follow a strict MVP pattern. This as yet unreleased framework's small size means that it should be very fast and embeddable. There will be lesser to learn and lesser proprietary idioms to understand due to its size.
We mentioned a few examples of what can be done in just 1kB. Even with such restrictions, some amazing creations can be made. Think of the possibilites without any such restrictions.