apcupsd was not ported to libusb-1.0 yet. As libusb-1.0 is not backwards compatible with libusb-0.1 - all function names are different, etc., porting needs a non-trivial amount of work. We already got rid libusb-0.1 long time ago. Now we have libusb-compat wrapper, which contains 95% of libusb-0.1 features. I am afraid that libusb-0.1 API is still widely used in third party enterprise applications.