No one cares if you print tickets at work. But the nature of communications, malware, and legal risks to an organization via computers makes it so monitoring computer activities makes sense to me.

But the official position of the company can’t be “everyone use the company’s resources as they see it for personal use”. So it’s best to just say company resources are for company. What if someone gets hurt using company machinery for personal use? In the US, that would be cause for the company’s workman’s compensation insurance premiums to increase. Why would an employer want that kind of headache?