Around here (Singapore), there are basically two roleplaying communities:
- The D&D community: These people play primarily D&D, sometimes for decades, with very little exposure or even awareness of what other systems exist.
- The "anything goes" community: They play a wide variety of game systems, narrative, mainstream, OSR, sometimes ongoing campaigns and sometimes short scenarios or one-shots, and often try out new things if the barrier of entry isn't too high.
Giving a pitch that boils down to "not D&D" doesn't work well for either of these - the first group sees nothing (majorly) wrong with D&D, and people in the second group often know half a dozen systems already, most of which are much more different from D&D than TDE is.
My experience here in the USA has been that The Dark Eye is a really tough sell to both of the communities you've identified.
It's much, much more complex (as a mechanical system) than the current edition of D&D, and, in this sense, The Dark Eye is more an alternative to Pathfinder than to D&D. But Pathfinder has a much larger presence here and is much better supported by its publisher than is The Dark Eye.
Folks in your second category are likely to have tried Pathfinder at some point if they are interested in fantasy game worlds. But, while Pathfinder is mechanically very different from (the current edition of) D&D, thematically it really isn't. The Dark Eye is thematically rather different, yet it's still quite obviously a traditional fantasy genre game
So I think, for both groups, you have to pitch it as an alternative to the fantasy genre games they're already familiar with (D&D or Pathfinder). "Realistic" is my way of doing that.
However, I'll admit I haven't had much success recruiting players to the game, so what do I know?