It is incredibly important as an IT person to be able to MITM your connections on a company network. And we fully employ such functionality where we are.
First and foremost, compliance is a thing. As a personal user you may not have to care, but as a business the organization has to take special care when handling certain types of information. So we need to be able to see where that information is going.
Another reason is for IPS. Many attacks, like spam, change the locations from which they come from. But a particular type of attack is almost never going to change. There are only limited ways, for example, to exploit any individual hole in a web browser. And you can flag on that to a degree that is significantly more successful than simply being able to block IP ranges, which is about all you get if you do not MITM connections.
There are real, legitimate concerns and reasons to MITM. If you don't like it, don't do non-company things on company Internet and equipment.