Don't buy hardware you can't run your own software on. Even embedded software.
There are tons of great routers, both consumer and business class that have Atheros CPU and WiFi chipsets that lack binary blob firmware, and support both Linux and BSD:
Are you imagining people developing an open-source vehicle-motor microcontroller firmware, and then users choosing what car to buy based on whether they can use that firmware? Because that's the kind of "hardware" we're talking about here.
I've always wanted to do that. I have a cheap, old car that uses a distributor right now. I doubt I'll find the time, but if I do, I want to make my own electronic ignition control system for it, just for fun.
There are tons of great routers, both consumer and business class that have Atheros CPU and WiFi chipsets that lack binary blob firmware, and support both Linux and BSD:
http://wiki.openwrt.org/toh/start https://wiki.freebsd.org/FreeBSD/mips
Pick software first, then hardware that supports it. It's how we do everything else, and routers are no different.