Why does RHEL7 anaconda not honor "xconfig --startxonboot --defaultdesktop=KDE" line and starts machine in Gnome post installation?

Issue

• Installing Red Hat Enterprise Linux 7 using kickstart file containing the following lines.

auth --enableshadow --passalgo=sha512
cdrom
xconfig  --startxonboot --defaultdesktop=KDE
ignoredisk --only-use=vda
keyboard --vckeymap=us --xlayouts='us'
lang en_US.UTF-8
network --hostname=newrhel7
rootpw --iscrypted $6$naiXhzfyCW2MWKUo$/S6idckbWajv2AJ8XpjBDBLntZy1U0vDyNrYlV7QMKFObkqTAHRdrF7xSBiWyinUHCw6WAwsnzp3OY9xL3J/f.
timezone America/New_York --isUtc
bootloader --location=mbr --boot-drive=vda
autopart --type=lvm
clearpart --none --initlabel --drives=vda
reboot
%packages
@^graphical-server-environment
@base
@core
@gnome-desktop
@kde-desktop
%end

• The line is there to boot the machine into KDE post installation, i.e. xconfig --startxonboot --defaultdesktop=KDE , still after installation finishes, the machine boots up into the gnome session.
• Why does RHEL7 anaconda not honor "xconfig --startxonboot --defaultdesktop=KDE" line and starts machine in Gnome post installation?