You are correct that I misremembered the behavior of LibreOffice Calc. But both Gnumeric and Excel failed to treat an exported CSV as having been "saved". Gnumeric's alert after I exported CSV and closed a worksheet was as follows:
Save changes to workbook 'test.csv' before closing?
If you close without saving, changes will be discarded.
Excel's was as follows when I exported:
test.csv may contain features that are not compatible with CSV (Comma delimited). Do you want to keep the workbook in this format?
*To keep this format, which leaves out any incompatible features, click Yes.
*To preserve the features, click No. Then save a copy in the latest Excel format.
*To see what might be lost, click Help.
Followed by this when I closed:
Do you want to save the changes you made to 'test.csv'?
LibreOffice Calc's was as follows when I exported:
This document may contain formatting or content that cannot be saved in the currently selected file format "Text CSV".
Use the default ODF file format to be sure that the document is saved correctly.
[X] Ask when not saving in ODF format
I assume these programs are referring to changes to column widths, formulas, and other things not typically represented in CSV.
What sort of moron do you take people for to think that you have to "protect" them from choosing a format of file that doesn't save layers
Any of the morons who reported "What happened to my layers?" through support channels.
and instead try to make them always save whatever they do in a format that no other programs support?
The same morons who pass around PSD files made in Photoshop. At least XCF has a reference implementation distributed under a free software license. Has Adobe released a spec or free library for manipulating PSD files? Which interoperable multilayer raster format were you recommending?
What on earth is the point of *banning* people from typing in a file with the suffix that they want to use in the save menu, and instead making them choose an entirely different menu?
If the names of the "Export" items on the File menu were changed to "Flatten and Save", would that satisfy you?
Actually two different menus, depending on context, only one of which has a keyboard shortcut.
Then you must have edited your keyboard shortcuts. My copy of GIMP 2.8.10 has keyboard shortcuts for export:
Export (Ctrl+E)
Export As... (Ctrl+Shift+E)
Create Template...