Direct3D made this a thing. Trying to draw unscaled 2D elements you often end up with blurry images as it bilinearly filters with the neighbouring pixels.

This is because of a mess with where it considered pixels located, where texture samples are considered located, and where, when rasterizing an included pixel, the texture coordinates sampled. See detail at [0].

If your graphics API was blurring all your images, you'd be passionate about that half-pixel offset too.

[0] https://www.gamedev.net/blogs/entry/1848486-understanding-ha...