My job at age twenty-two wasn't boring. My entry-level job at age seventeen wasn't boring. Granted that I got lucky, it still disproves the notion that this is a cosmic necessity.
That having been said, the relevant concept isn't boring, it's inefficient. Cleaning toilets is boring but someone has to do it anyway. What people are complaining about here isn't that they were doing boring but necessary grunt work, it's that they were doing unnecessary grunt work that could have been automated, that their time was being wasted.
If your job can be automated, automate it. If your manager reacts negatively (and not by pointing out problems you weren't aware of), that means he's incompetent, dishonest or both. In that case, start looking for another job. Life is too short to work for incompetent, dishonest people.