So what's actually wrong with this code?
APM is still in the range of things we support, and that standard hasn't changed in a long time.
Many early ACPI machines are now blacklisted as being too old, so we can only run APM on them (though not all of them). FreeBSD still runs on these systems, but 12 will likely be the last release for them since the coming purge will likely prune device support past the point of viability for these machines (plus many have issues running a full range applications that will just get worse as we get into the 13 release). At that time, I agree that this might be a good candidate to evaluate for removal, but not being updated in a along time is not a compelling reason to me.