[rxh4n1]

“Can anyone give a credible explanation of why aliens would want to visit earth?’

Lots of reasons have been used in sci-fi.
To eat us: “To Serve Man”.
“We’d Make Great Pets”.
To watch us for entertainment (Star Trek TOS).
To steal our resources.
To kill us and steal our planet.
We have hot chicks.
To warn us against threatening the rest of the universe.
To put us in zoos (Slaughterhouse Five).
Feed off our violent nature (Predator).
To breed with us.

[DugwayDuke]

rxh4n1 wrote: “Lots of reasons have been used in sci-fi.”

All of which assume faster than light drive.
Now why would an alien race want to travel 100s of years to travel here?

[GingisK]

“Can anyone give a credible explanation of why aliens would want to visit earth?

We are their science experiment.
The excitement, like a good Everest climb.
To see if the rumors are true
Waiting for trade embargo to be lifted, smuggling goods.