Littlebits is considerably more expensive than the micro:bit.
They are very much a publicly funded corporation, so everything they do has to fit with that.
You can drive larger displays https://github.com/carlosperate/awesome-microbit
Plus don't think it's the only computer they'll have, it's an IoT computer, it's supposed to not have a video out.
I like that it's all in one, you can program it in 5 mins with a browser, and yet connects to real IO the same way real embedded computers do, you have to get a bit messy, you know it's not a toy.