Is there any science fiction screenwriter who knows how BIG space is?

The audience for this movie doesn't care.

The research for this movie probably consisted of watching other movies... Or maybe a bit of Star Trek. I swear, when I first read about this one and saw the images posted, I thought - "Well, they land on an alien planet of dinosaurs and by the end of the film, two of them survive; a man and a woman." Cuz, that would be an original concept, right?

As of now, I don't care. It has dinosaurs and it looks like fun. I'll just assume it is stupid and hope that it is not that stupid.

You are going down a dangerous path... we're talking about someone from a different solar system who looks exactly human and also speaks English.

I was thinking they could have had him accidentally wander into an unknown wormhole that took him back in time. That solves some problems but creates others. At least the "velociraptors" were sized appropriately unlike in Jurassic Park

This is the classic case of knowing a Little about something, and allowing that to lead you down a hilariously irrelevant path.

I could go on at length, but the short version: it NEVER makes sense to complain about unlikely generative events that happen in novels, movies, plays, or any other narrative fiction.

Stop and think. No, really. STOP. Now Think About It: is it EVER reasonable to arch an eyebrow at a a story that proceeds from something really, Really, REALLY unlikely happening? (Hint: NO.)

It's the obverse of the absurdity coin, where people complain that something is Too Common/Familiar.

That is all.

yes, Douglas Adams did

Movie plot needs to happen and they had to bring him somehow on Earth.

The real mistake they make is forgetting about relativity. If they can travel fast enough to get between star systems in a few years, they will be going so fast they will age much more slowly than the families they left behind. Not to mention that years that messages would take to get back and forth -- messages can't travel faster than light.

The only thing I can think of is that from my general understanding, the galactic disk is 100 times wider than it is thick (100,000 light years across, 1000 thick).

It could just be that space travel is normally just done within the galactic disk for who knows what reason -- some means of travel efficiency to avoid the extra travel distance of traveling out of the disk to cross it, and then re-entering it? Some kind of navigation benefit? Some kind of resource or energy acquisition during the trip?

The thing I found strange about it was why the sensors and navigation system didn't detect the asteroid and debris field and just navigate around it. I would imagine that if your deep space vessels routinely pass through solar systems your odds of encountering uncharted rocks are relatively high.