Primarily, I wanted to make a simple notepad editor, not a hex editor. Binary editing is a feature, but not the main purpose. Many other text editors use escape characters to mimic the way that hex editors edit text, and while this is a very rational solution, I wanted a simple but elegant solution that would allow full control while not adding in a lot of overhead, and I came up with this one. Every character is still distinguishable for the most part, but the main purpose was always to display it as legible text rather than hexadecimal.
The binary editing is there in case a file of yours gets corrupted or if you just want to see the insides of a given file in a human readable way. I used to use windows and one of the things that got me into programming was the realization that all files were simply data on the inside, something I explored using windows notepad. As for gedit, I was previously using leafpad and so the binary editing is meant to be a step up from leafpad’s inability to show data, not gedit’s capable escape sequence system.