What is the primary purpose of a file explorer? To find and view a file. It's called 'Finder' not 'Renamer'.
Please tell me a graphical file explorer (and there is probably 100 of them since the dawn of windowed OSs) where ENTER does not open the file that is not Finder. Please tell me one example. Maybe a dedicated file-rename-utility?
If you have a tree of files in an IDE on a sidebar, and you're navigating the tree with arrow keys, and you press Enter. Should it prompt to rename the file or display the source code file you selected?
If you have a image viewer that is showing a grid of image thumbnails and you are navigating them by arrows. You press enter with a thumbnail highlighted. Does it open the image, or prompt you to rename it?
You have selected "Open a file" from practically any GUI app and it displays a File Picker, which is basically what Finder is. As you navigate the grid/listing/whatever, and highlight a choice and hit ENTER, what do you expect to happen?
If you interact with listing or grids or displays of files or objects and have one of them highlighted, and hit ENTER in 99.99% of programs (number made up on the spot by me), does it open/activate/display/expand/select the item, or rename it?
Finder's behavior in this instance doesn't just go against other operating systems' file pickers/navigators, it goes against practically any navigate-items and select-by-pressing-Enter GUI paradigm in virtually every GUI program in existence.
The rename operation is so rare compared to select/open/activate that it is reduced to a hotkey or function key in virtually every other app, OS, and dialog.