[II2II]

The analysis was done on \Windows\explorer.exe, and it was noted as being an extreme case. The distinction is important for a couple of reasons. First, it is an extremely small part of Windows as a whole, weighing in at about 4.5 MB on disk (Windows 10 AE). Second, chances are that it is also a very small part of what people think of as Windows Explorer since it also depends upon external libraries.

While Windows may suffer from unnecessary bloat, this article is not a very good evidence in that direction. Windows itself is much (much) more than a 4.5 MB binary and the growth of Windows over the years likely has more to do with changes in technology and the market than anything else.

I also doubt that this is an indicator of sloppy software development, nor is this basic stuff. It simply indicates that the resources were added to the executable file more-or-less as is. Developers are unlikely to be concerned with the structure of the resources as long as those resources are in a format that is well understood by the software. Graphics designers are unlikely to be concerned with how the embedded data bloats the size of the executable. While stripping the excess data may seem like a basic good practice in retrospect, it is not basic nor is it sloppy in the sense that it doesn't strictly fall in the domain of the two groups responsible for handling the data.