command line - Why does Ubuntu show boot messages when starting up?

When I boot Ubuntu or Fedora, they show a black screen with a bunch of [OK] messages for startup processes.

It seems like an old style DOS system. Nowadays, iOS and Windows don't show those terminal-like results. Elementary OS doesn't show it (most of the time) either.

Can I hide them in Ubuntu?

The answer to this question doesn't work in my case because my /etc/default/grub already has GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" but it still shows the boot text.

Output of apt-cache policy plymouth | grep Installed:

Installed: 0.9.2-3ubuntu17

Here's my /etc/default/grub

GRUB_DEFAULT=0
#GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi=force"
GRUB_CMDLINE_LINUX=""

Update 7 Mar 18:

After running:

sudo apt-get clean, apt-get autoremove, apt-get update, apt-get upgrade

The result is the same:
First Ubuntu boots with the logo and 5 loading dots
Then, the screen show these:
(a lot of them)

...
[ OK ] Started CUPS Scheduler.


[ OK ] Started Run anacron jobs.
[ OK ] Started ACPI event daemon.
[ OK ] Started Set the CPU Frequency Scaling governor.
       Starting Hold until boot process finishes up... any system changes.pp link was shut down.

Then Ubuntu shows login screen with username.

Also:

$ sudo dpkg-reconfigure -a
[sudo] password for user: 
Unknown option: a
Usage: dpkg-reconfigure [options] packages
  -u,  --unseen-only        Show only not yet seen questions.
       --default-priority   Use default priority instead of low.
       --force          Force reconfiguration of broken packages.
       --no-reload      Do not reload templates. (Use with caution.)
  -f, --frontend        Specify debconf frontend to use.

  -p, --priority        Specify minimum priority question to show.
        --terse         Enable terse mode.

$ sudo dpkg-reconfigure plymouth
[sudo] password for user: 
update-initramfs: deferring update (trigger activated)
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
Processing triggers for initramfs-tools (0.125ubuntu12) ...
update-initramfs: Generating /boot/initrd.img-4.13.0-36-generic

short answer: yes! :) you can customize Ubuntu or Fedora whatever way you like.
I don't know what version you are running, but under any normal installation i believe plymouth should be installed.

Plymouth is the application which provides the graphical "splash" screen when booting and shutting down an Ubuntu system.

There is an entire Wiki on this topic on the ubuntu website here:
https://wiki.ubuntu.com/Plymouth
I think the reason yours is not working is because either the kernel is not set up to use plymouth correctly, or your grub bootloader was set up to boot the os in text-mode.

Another issue i've encountered before myself, is that my Ubuntu wasn't shut down properly, which causes it to boot in a system check, and that also shows the terminal output.