Welcome Rainier, it'll be nice to have your kind of perspective on things.
I suppose ultimately we have little (credible) evidence for UFOs; the only tangible evidence being crafts that have crashed. Without proper analysis however, we can't determine the origins of any of this evidence.
This is why such interest is placed in the abduction area. The thinking is if you can't prove UFOs, but you can prove Aliens, then the rest is proved by default.
Thats all for now!