Why would anyone bother with making Linux from scratch? With all these distros with almost everything you need, people still choose to build Linux from source. There are people who say that they get a more optimized system that way. Others want it because of the control that they have over the system. I know of one person who built Linux from scratch and it took him a long time to do so and if I recall correctly he couldn’t really use his computer for a week because he did something wrong and it was his problem at the time.
Looking at the Linux From Scratch website, these are the benefits of installing it from scratch:

You understand Linux better because you learn about the ins and outs of the system.
You get a more compact system.
It is a more flexible system because you can do anything with it.
You […]

Full story: Clair