[appropriate CCs added]One reason was that there are (were?) a number of machines which only powered down properly using apm. It was discussed as part of shutting down after power failure when your UPS is running out of power.
On Friday, 13 April 2007 02:33, Robert P. J. Day wrote:just something i threw together, not in final form, but it represents
tossing the legacy PM stuff. at the moment, the menuconfig entry for
PM_LEGACY lists it as "DEPRECATED", while the help screen calls it
"obsolete." that's a good sign that it's getting close to the time
for it to go, and the removal is fairly straightforward, but there's
no mention of its removal in the feature removal schedule file.
It's been like this for a long long time. I think you're right that it can be
dropped, but I don't know the details (eg. why it hasn't been dropped yet).