The original was “Ultimate Soundtracker,” and it was so influential that derivatives often named themselves ___tracker (noisetracker, screamtracker, impulsetracker)

Ahoy on YouTube has a great video about tracker music, https://youtu.be/roBkg-iPrbw

The term probably arose from the naming, starting with the very first one: Soundtracker (1987) on the Amiga, obviously a play on the word soundtrack. From there we got Noisetracker, Startrekker, Protracker, Fasttracker (MS-DOS) and so on.

I think Ahoy answers the question in this video [1]. I'm not sure and I'm watching it again to check

EDIT : Wikipedia says the first one was called Ultimate Soundtracker so probably from that

[1] Trackers: The Sound of 16-Bit : https://www.youtube.com/watch?v=roBkg-iPrbw

I can't say much about the early history, but trackers have a unique UI compared to other DAW software. Instead of a staff or piano-roll, the tracker UI looks more like a spreadsheet, with each column being a channel, each row being a step, and each cell containing a note or effect.

This representation meshed well with early demoscene music storage and code, and evolved into its own subculture in the late 80's and early 90's.

See https://en.wikipedia.org/wiki/Music_tracker

Or because you use it to make soundtracks.