I have read the whole thing, and I'm not sure what you would build with it. Can anyone give me some examples? I'm genuinely curious.

Pretty much anything you could use Linux for, except high performance stuff since the ARM SoC they've chosen is somewhat limited.

I look at it as a platform for solutions to technical problems, where either or both the solution and the problem are temporary in some sense. You could plug it into an ethernet port and have it automatically sniff the network for a while, or be your television box in hotels, or a leaner companion to some Kraken style SDR device than a laptop, or whatever.

Once you have a purpose which is more permanent, then you'd probably switch it out for another device.