HI Andreas,
Using "-j .text" would only keep the .text section, as your string is in the .data section, the actual contents would have been removed and you would expect your string to be just noise (as you saw). "-R .eeprom" would copy all sections apart from .eeprom which would mean that your .text and .data would remain intact and your program work as expected. Judging by your assembly file I don't see any section change to .eeprom so this may have actually done anything.
In general, I would expect using neither -j nor -R would in most cases produce a working file, but there may be some cases where it is useful to know which of these to use. When you need them, -j is for when only a list of known sections are needed, and -R is for keeping everything except a given section.