If you ever want an answer you don't understand, many of the programs involved are open source, meaning that it is both a) possible to figure out why they don't do the thing you want and b) at least in theory, possible to change them. However, they're quite old and a bit impenetrable, so, the best I've been able to do is figure out vaguely how something probably works. So, feel free to chuck any mysteries my way and we can maybe get some idea of the reasons behind it.
Plus, whatever abcm2ps.exe your ABC editor has is probably super out of date compared with the one packed into your ABC editor of choice:
My ABCExplorer has
abcm2ps-5.9.25 (November 2, 2011)
My EasyABC has
abcm2ps-8.13.14 (2017-08-05)
And current result bug fixing development puts the current version at v8.14.7 from February this year, but, I don't have a suitable build environment for C or C++ right now to build an updated version to see if would even be compatible.