bin/onos-server does not start ONOS correctly if /opt/onos exists

If you follow the instructions and/or screencast here

https://wiki.onosproject.org/display/ONOS/Installing+ONOS+from+onos.tar.gz+file

then ONOS will probably not start up correctly as expected if /opt/onos exists and is empty or an old version of ONOS:

$ sudo rm -rf /opt/onos
$ sudo mkdir /opt/onos
$ bin/onos-service server 1>/tmp/stdout.log 2>/tmp/stderr.log &
[1] 12752
$ cat /tmp/stderr.log
touch: cannot touch ‘/opt/onos/apps/org.onosproject.drivers/active’: No such file or directory
touch: cannot touch ‘/opt/onos/apps/org.onosproject.drivers/active’: No such file or directory
touch: cannot touch ‘/opt/onos/apps/org.onosproject.openflow/active’: No such file or directory
touch: cannot touch ‘/opt/onos/apps/org.onosproject.fwd/active’: No such file or directory
touch: cannot touch ‘/opt/onos/apps/org.onosproject.proxyarp/active’: No such file or directory
touch: cannot touch ‘/opt/onos/apps/org.onosproject.mobility/active’: No such file or directory
bin/onos-service: line 44: /opt/onos/apache-karaf-3.0.3/bin/karaf: No such file or directory
[1]+ Exit 127 bin/onos-service server > /tmp/stdout.log 2> /tmp/stderr.log

It doesn't seem to respect an explicit path to the onos-service script, nor the setting of the ONOS_HOME variable, and instead uses the incorrect directory in /opt.