Refreshing the parts other SBCs can't reach
> Why would potential customers be interested in x86, if they're not tied to Windows?
Well that's the key, isn't it? Say you're an OEM making annunciators for trains, or portable ATMs, or things that trundle round warehouses following lines on the floor. If your *current* products are based on WinTel technology and you want better, faster, cheaper, more reliable, more power and a board that hasn't recently gone out of production then yes: this could be for you.
If you're upgrading an existing product or giving it a mid-life boost you don't want to spend vast amounts of developer time (and time to market) redeveloping stuff, checking if drivers will still work and integrating peripherals, USB thingies and so forth. You just want to drop in a new "heart" to the machine and get it out the door.
However if you're building a mass-market product where space, power consumption and unit-price are more important and you're writing all the software from scratch anyway, then you probably wouldn't consider this board.