[dkersten]

RethinkDB themselves pivoted away from this

I believe the storage backend remained largely the same (ie current RethinkDB, IIRC, is still optimised for SSD). Maybe I'm mistaken.

[SamReidHughes]

It's the same storage backend (well, modified quite a bit) and optimizing for SSD's isn't really the goal anymore, especially since things are now stored in a file and not the whole block device, and O_DIRECT is turned off.