Of course it defeats the purpose of chromebooks - simple cloud managed machines - but hey, why not?
You have to more or less root the device... press a Ctrl key combo during every boot in order to keep it rooted... and then open a shell and type a sequence of commands to enter a crouton Linux session.
Look, I have fond memories of using Slackwhare back in the 90's, and feeling like a wizard every time I figured out how to make my PC do something it wasn't "supposed to do". So I assume that hacker ethos is much of the appeal.
However, today Acer sells the Aspire One Cloudbook for the same price as the Acer Chromebook I bought two years ago. It's 14" instead of 11", has the same battery life, and is a full unlocked Windows PC (easily replaceable with Linux). So if you just want a cheap Linux PC with good battery life, why in the world wouldn't you go that route rather than buying a locked Chromebook and jumping through all the hoops? Using a Pixel would be even more bizarre, because at that point you're in the Macbook Pro price range.
Chromebooks are well-suited for school students, and non-technical business people at companies that revolve around Google Apps. You CAN squeeze those square pegs into round holes as a programmer, but it really doesn't make any practical sense to do so today.
The only real downside is the 64GB SSD, but I can augment that with an SD card. I'm pretty deeply in love with this laptop as a development machine.