The real answer

The real answer won't seem to make much sense, but it's where RIP comes from.

Macs are great for graphics. People working in professional graphics work with commercial printers. Commercial printers take digital designs from Macs and convert them into something they can print with. This conversion involved taking vector based shapes (shapes described by math) and converting them into a matrix of dots. The resulting grid of dots is called a RASTER image. All images are either RASTER or VECTOR.

Here we get to the meat of the definition:
The act of converting vector images into raster images for printing is called "Raster Image Processing". the abbreviation for this is "RIP", and the abbreviation was commonly used in the Mac world to describe where a job might be in the production phase. A printer would say, "We're ripping the job right now!" This term is so ubiquitous in the industry that anyone in the field knows it.

Ripping is done by computers in a sometimes time consuming automatic process. This start-it-and-walk-away process feels a lot like converting AIFF files into MP3s. Especially in the early days of MP3s when computers took longer to do the work.

Ripping a graphics file from one format to another is a lot like converting music from one format to another. The basic content is the same. It's just been converted to work in a different way.

Mac used "RIP" in their campaigns to describe the audio file conversion process because almost all of their customers understood what RIP meant. The Mac rules supreme in the print graphics world. I'm not aware of any other company using the term (before Apple) to describe the creation of MP3s from a CD source.

I'm certain this is the origin of the phrase RIP. It was the closest analog they could find to describe the MP3 conversion process, and their "Mac only" customers understood what it meant.