I have often found eponyms confusing and I try to avoid them when a good alternative exists. Take "Gibbs free energy" as an example. I had trouble remembering what it is compared to "Helmholtz free energy", but then I learned that "Gibbs free energy" is actually "free enthalpy", at which point I could remember it more easily. Perhaps my point isn't that eponyms are bad, per se, but that it is much better to have descriptive names if possible, and better yet to have self-discoverable and structured names.
Stigler's law [1] also exists, and I have found far too many eponyms to be named after people who had nothing to do with the concept (and sometimes they did not want their name attached to it even).
Eponyms have the advantage of being short and simple. Descriptive names can be pretty wordy. Take "Mach number" as an example. Surely I can call it the "ratio of the velocity to the speed of sound", but that's pretty much the definition at that point. "Mach number" saves a lot of space. Terms like "sonic number" or "sonic ratio" could also work, but everyone already knows what the "Mach number" is, so there is no point in introducing a new word needlessly and sowing confusion (in my opinion).
Stigler's law [1] also exists, and I have found far too many eponyms to be named after people who had nothing to do with the concept (and sometimes they did not want their name attached to it even).
Eponyms have the advantage of being short and simple. Descriptive names can be pretty wordy. Take "Mach number" as an example. Surely I can call it the "ratio of the velocity to the speed of sound", but that's pretty much the definition at that point. "Mach number" saves a lot of space. Terms like "sonic number" or "sonic ratio" could also work, but everyone already knows what the "Mach number" is, so there is no point in introducing a new word needlessly and sowing confusion (in my opinion).
[1] https://en.wikipedia.org/wiki/Stigler%27s_law_of_eponymy