For quite a long time, there was a Linksys WRT model that remained in production long after its useful life (because it had old radio standards and was slow and because newer devices were much cheaper with greater capabilities) because it ran Linux, and could be hacked very easily and could use all Open Source drivers and such. It's even where "OpenWRT" got the WRT in its name.

So, there's definitely a market for it. But, I don't know that it's comparable to the market for consumer oriented devices. It'd be nice if consumers were smarter and knew enough to demand this kind of thing.

It'd be really nice if one could go to the store and buy a router running OpenWRT or Tomato or whatever, like you can go to the store and ask for an Android phone or a Windows PC. As operating systems go, many current routers are probably more complex than DOS or early Windows versions and certainly more complex than many early phone operating systems. Not sure why nobody has thought to make the OS a competitive factor for routers.