For the following reasons don't install or recommend Ubuntu.

1. Development of Ubuntu is led by Canonical, Ltd. a UK-based "trading" company which generates revenue through the sale of "technical support" and "services."

2. By installing users agree to allow Ubuntu's parent company Canonical to collect user search data and IP addresses and to disclose this information to third parties including Facebook, Twitter, BBC and Amazon.

3. The adwares and spywares introduced in Ubuntu violates user's privacy and is one of the rare occasions in which a free software developer persists in keeping a malicious feature in its version of a program.

4. Whenever user searches the local files for a string using Ubuntu desktop, Ubuntu sends that string to one of Canonical's servers.

5. Ubuntu has received widespread objection from the open source community for violating free system distribution guidelines.

6. Canonical disgruntled upstream open source developers by introducing Mir, their own display server not derived from X11 or Wayland.

7. Ubuntu's policy prohibits commercial redistribution of exact copies of Ubuntu, denying the baseline freedom.

8. Ubuntu is basically Debian with extra "cool" look and is not binary compatible with Red Hat Enterprise Linux and CentOS which are used for most scientific development.

references:
en.wikipedia.org/wiki/Ubuntu_(operating_system)
gnu.org/philosophy/ubuntu-spyware.html
phoronix.com/scan.php?page=news_item&px=MTMxNzY
gnu.org/distros/free-system-distribution-guidelines.html
linuxlock.blogspot.com/2013/05/ubuntu-and-their-uck-y-problem.html