I am not sure if this is a regression of some kind and I don't know when it started happening, but I know that it wasn't always this way:
When using the shortcut-based system screenshot tools, I get png files on my desktop. Before retina Macs, these were all at pixel density 72 ppi. On retina Macs, these screenshots started becoming 144 ppi.
At some point not that long ago, the window screenshots (that's shift + command + 4, then space) of certain types of windows (ex. Finder, Chrome) now produce images at 72ppi, while window screenshots of other types (ex. Inspector in Preview) produce images at 144ppi, and all of the other screenshot types of windows (entire screen and rectangular selection screenshots) still produce images at 144ppi. When did this happen and is it a software regression or intentional?
For claims of intentionality: please provide authoritative documentation as support.