You're absolutely right, but even more so, there's the hilarious reality that "exogenous" is one of a select few words we Kiwis identified as "Wu words", which Johnny Flynt likes to abuse in writing when much simpler words would suffice and are, as you suggested, actually better suited meaning-wise.
I dunno if I can remember more than just a few, my Wu-memory seems to be exogenous from my brain tonight, so call goes out to
@Jaimas ,
@Cynical,
@Francis York Morgan and anyone else:
1. -The ever-popular "exfiltrate"
2. -"exogenous"
3. -"heuristics" in that venomously uncalled-for patronizing on the Susan's Place troon forum.....
4. "frangible", as if Johnny understands ballistics...
.....
...Any I'm missing? Help pad out the Wu-cyclopaedia! (Maybe the "No-Dick-tionary"? Nah, too obvious!)