Because not many people care (yet). Of course font should always be defined in physical units (be it pt, inch or mm). Pixels are irelevant. When you are printin

Because not many people care (yet). Of course font should always be defined in physical units (be it pt, inch or mm). Pixels are irelevant. When you are printing a text, you also don't care about how many pixels are being printed - your printed page will look the same on any printer, you can print a ruler. But somehow software industry has ignored this for decades. Why? I don't know. Probably inorance, bad cooperation amd lack of standards.