NVMe is certainly not more complex than either AHCI or SAS from a driver or hardware interface standpoint. And I've written drivers for all three that run in pr

NVMe is certainly not more complex than either AHCI or SAS from a driver or hardware interface standpoint. And I've written drivers for all three that run in production today. Now maybe the controller design is more difficult - I wouldn't know - but there are several vendors that sell NVMe controllers out there so it can't be all that bad. And as noted in the other comments, this is about simplifying support for things like connectors, LEDs, expanders, and software in data centers where they're mixing NVMe SSDs and HDDs today. It's just simpler to have fewer parts and software differences.