[1] It gets its name from the characteristic speech patterns of Finnish athletes of the 1970-90s, especially rally drivers such as Markku Alén and Tommi Mäkinen.
It may derive from the conventional methods of language teaching based on written materials such as text books, which better facilitate the learning of reading and writing than of pronunciation or intonation.
[4] Rally English places more emphasis on conveying meaning than sounding 'correct'.
[2][4] It is both looked down upon as an 'unsophisticated' way of speaking a foreign language, and, conversely, praised for pragmatically prioritising information over aesthetics.
[4] It can also be a source of embarrassment, or mirth, depending on the speakers or observer's viewpoint.