In addition to what other folks said, a big part of the user base for OpenWrt and similar use standard hardware from the big consumer electronics firms. I can i

In addition to what other folks said, a big part of the user base for OpenWrt and similar use standard hardware from the big consumer electronics firms. I can imagine someone maintaining a port for random experimental platforms (assuming the codebase is amenable that sort of thing; I have no idea), a large part of the point of it for a lot of users would be gone. But as others said, I can't imagine a Pi having anywhere near the throughput of the commodity AC APs I use at home at this time.