Agreed. After over 20 years of software engineering, I spend less time coding than the other things you listed above. As a "senior" engineer you are often leaned up for other important tasks, such as research, mentoring, code review (very important), estimates for the business, and more.
You did the right thing to say no. These are people that haven't grown enough to understand that the nature of software development is a very creative and learning-driven endevour. Cheers to you!