Hi there, @nsweeten ...
I realize you cannot please everyone. That's not what this is about. The selection needs to be more carefully considered for all of your subscribers. Please consider that you end users are encountering the results of programming decisions (most likely) made by programmers who do not deal with thee repercussions of their selections. This information will be meaningful to the right person or group, and I do not mean the "voting" community.
I may be interpreting this paragraph wrong (and if I am, I apologize), but it sounds like you're assuming that I work for Instructure and have input into the decision-making process of what gets developed, what gets set as "defaults", etc. I actually work for an arts college in Michigan, and so I don't have much knowledge on why notification settings are set the way they are for "defaults".
The defaults for notification settings are all listed in this document: How do I manage my Canvas notification settings? (see the link in the last bullet point within the light blue section of this Guide).
I searched the Community, and I found a couple existing ideas that have already been submitted (one has been archived, though) which might be similar to what you are requesting:
This first idea I linked to has been added to a larger theme which you can find at:
I'd encourage you to follow both the idea and the theme so that if it comes up for voting in the future, you'll have an opportunity to be a part of that process.
I hope these links and resources will be helpful for you in some way.