Also to understand it you have to think about typewriters, printers, and then text terminals. With a typewriter a cartage return with no line feed could be desirable if you are editing or using strikethru chars. Or on a CRT going to the beginning of the line to overwrite whatever text was there could also be a desirable thing. Then add in the mix of a dozen different companies making things and it was a recipe for 'you get all the different ways'.