Why x0vncserver is not starting at boot?

I tried to make my tightvncserver start at boot on parabola arch Gnu/Linux in an auto GUI login setup using the wiki and by creating x0vncserver.service systemd unit following that and then systemctl enable x0vncserver.service but when I boot/reboot, I see no vnc server active and then checking I see this

# systemctl status x0vncserver.service
* x0vncserver.service - Remote desktop service (VNC)
   Loaded: loaded (/etc/systemd/system/x0vncserver.service; enabled; vendor preset: disabled)
   Active: inactive (dead) since Sat 2017-07-01 20:42:55 +06; 1min 34s ago
  Process: 302 ExecStart=/usr/bin/sh -c /usr/bin/x0vncserver -display :0 -rfbport 5900 -passwordfile /home/peruvian/.vnc/passwd & (code=exited, status=0/SUCCESS)

Jul 01 20:42:52 sky systemd[1] : Starting Remote desktop service (VNC)...
Jul 01 20:42:55 sky systemd[1] : Started Remote desktop service (VNC).

and my

# journalctl -xe | grep vnc
-- Subject: Unit x0vncserver.service has begun start-up
-- Unit x0vncserver.service has begun starting up.
-- Subject: Unit x0vncserver.service has finished start-up
-- Unit x0vncserver.service has finished starting up.
Jul 01 20:47:08 sky systemd[1] : x0vncserver.service: Main process exited, code=exited, status=1/FAILURE
Jul 01 20:47:08 sky systemd[1] : x0vncserver.service: Unit entered failed state.
Jul 01 20:47:08 sky systemd[1] : x0vncserver.service: Failed with result 'exit-code'.

But if I run the command systemctl start x0vncserver.service or systemctl restart x0vncserver.service after loading the desktop, it works without any issue as the # systemctl status x0vncserver.serviceshows

# systemctl status x0vncserver.service
* x0vncserver.service - Remote desktop service (VNC)
   Loaded: loaded (/etc/systemd/system/x0vncserver.service; enabled; vendor preset: disabled)
   Active: active (running) since Sat 2017-07-01 20:56:53 +06; 2s ago
  Process: 924 ExecStart=/usr/bin/sh -c /usr/bin/x0vncserver -display :0 -rfbport 5900 -passwordfile /home/peruvian/.vnc/passwd & (code=exited, status=0/SUCCESS)
 Main PID: 925 (x0vncserver)
    Tasks: 1 (limit: 4915)
   CGroup: /system.slice/x0vncserver.service
           `-925 /usr/bin/x0vncserver -display :0 -rfbport 5900 -passwordfile /home/peruvian/.vnc/passwd

Jul 01 20:56:53 sky systemd[1] : Starting Remote desktop service (VNC)...
Jul 01 20:56:53 sky systemd[1] : Started Remote desktop service (VNC).

and my default.target is

# systemctl get-default       
graphical.target

I guess the service starts earlier than it supposed to and fails due to lack of resources at boot.