4. Forgotten Roots
You have to drill down deep on Canonical and Ubuntu's sites to find any mention of Linux. If you didn't already know, you might assume that Canonical had built Ubuntu from scratch, instead of assembling it from the efforts of Debian and hundreds of other projects. Even "open source" is barely mentioned.
The reason for these omissions is obvious: Canonical is selling Ubuntu, not Linux. Promoting Linux doesn't benefit Canonical in any direct way. However, to members of the FOSS community, the omissions look ungrateful, a rewriting of history that distorts what actually happened.
5. Ads on the desktop
If Linux desktops have anything in common, it's the absence of ads and logos. Yet over the last few releases, Unity has been returning ads to the desktops — ads for Ubuntu services like Ubuntu One and the Ubuntu One Music Store, and, more recently, for Amazon and other affiliate services.
These additions remove the rationale for positioning the launcher on the left side of the screen, since on many screens they force users to scroll down to see the complete collection of default icons.
More to the point, these ads are exactly what many people hoped to avoid by moving to the Linux desktop. Naturally enough, Canonical prefers to describe them as services, but users continue to recognize them for the ads they are.
6. Privacy and Security Issues
In the 12.10 release, Canonical entered into an affiliate agreement with Amazon. Under the agreement, search results from Amazon appear when users search their local hard drive. In the upcoming 13.04 release, this feature is going to be greatly expanded, with results from dozens of other companies appearing unless users turn the feature off.
This feature has not only been criticized as a needless distraction and a reduction of Ubuntu to adware, but condemned as a major invasion of privacy by both Richard Stallman of the Free Software Foundation and the Electronic Frontier Foundation. The criticism has resulted in modification of the function, but it remains in place.
Canonical's response is that users should simply entrust their data to it. However, the issue is not whether Canonical or any other corporation is trustworthy, but that basic security suggests that no one should be entrusted with your data. Consequently, the feature is seen by many as a simple cash grab.
7. Introducing Proprietary Elements
The FOSS community often has a inconsistent response to proprietary software. On the one hand, FOSS is supposed to provide an alternative. On the other hand, many distributions have compromised their anti-proprietary positions in order to get working hardware drivers and audio codecs.
Over the years, Ubuntu and its commercial sponsor Canonical have introduced proprietary elements. These elements include the original Launchpad code, some drivers and codecs, and, most recently, the shopping lenses planned for the 13.04 release.
However, much of the reaction seems due to the rhetoric with which such concerns have been answered. While Canonical's and Ubuntu's home pages emphasize open source and freedom, founder Mark Shuttleworth has commented on Slashdot that, "The people who rant about proprietary software are basically insecure about their own beliefs."
Similarly, early in his career at Canonical, community manager Jono Bacon defended Canonical and Ubuntu by suggesting that proprietary elements are needed just now to make Linux competitive — and never mind that Ubuntu has never hesitated to finance the things Canonical has defined as necessary for commercialization.
Whatever the justification in such defenses of proprietary software, they are a far cry from Mark Shuttleworth's claim when Ubuntu's first release was announced that it was "absolutely committed to free software." Inconsistency, no matter how good the reasons for it, is always apt to draw criticism.