Stallman’s post, "The ads are not the core of the problem," "The main issue is the spying. Canonical says it does not tell Amazon who searched for what. However, it is just as bad for Canonical to collect your personal information as it would have been for Amazon to collect it."
According to Stallman, the mere fact that Canonical chose to include malicious code in Ubuntu is damaging to the entire free software community, because users have come to expect that community oversight means free software won't contain malware.
Ubuntu allows users to switch the surveillance off. Clearly Canonical thinks that many Ubuntu users will leave this setting in the default state (on) and many may do so, because it doesn't occur to them to try to do anything about it. Thus, the existence of that switch does not make the surveillance feature OK.