[vforvendettador]

There's a lot more to building laptop than putting different components together. Portability, mobility, heat dissipation, design to put as many things as safely (and profitably) possible etc.

Building a desktop is relatively easy. Desktop is designed to be stationary and it's a lot more forgiving when connecting parts. There's a lot more room to manoeuvre and for heat dissipation.

I think to achieve the purpose, where end-user will be able easily customise a laptop will require a larger footprint and won't be appealing to many users.