What they're really missing is a midrange product for a midrange price. I can't blame them for avoiding the low end, but can't I get anything for less than $2000?
So while it's unfortunate, it's not a case of ignoring the low end deliberately but mostly flows from the economic realities of not having anywhere near the addressable market of x86 or ARM. The small community of ppc64(le) enthusiasts is very much hoping for a future where this changes, however small that chance might be...
This seems to be universally true for all kinds of UNIX workstations and servers.
Repeat until the hardware is rare and worth something?
IIRC some of the latest AMD boards to end up with coreboot support is using opterons from 2011-2013.