Didn't believe corny first contact film as a kid when it came out.
Why people want to watch rose tinted film back then?
Even I knew on European explorers, adventurers & settlers changed pre-industrial societies extrapolated into nothing good.
Easily understood US government's reaction to E.T given they did to many cultures & possibility of no resistance to new or mutated diseases via cross-contamination.
Comment
E.T., the Extra-Terrestrial