I think it is scarier when you don't know where they can pop up and even trying to sneak past them to get to the crashed ship can be pretty harrowing. Apparently it's possible for those guys to migrate if you mess with their AI in the wrong way, to the point they are hanging out in the shallows. But yeah, I think they wanted to mitigate their lethality by restricting them to certain areas. Imagine there's a mod that lets them move around the map though.Ill have to look into that. The premise of the game is great, the execution is just a little slow and shallow. They make a big deal of the reaper leviathans, they're the real deal legit big bad. Okay where are they? Oh a few over there, and a few over there. Okay do I ever need to go over there? Once, in the beginning of the game. And do the reapers ever travel to other locations? Nope, they're just over there. And I have no reason to ever go back there? None. So they're not really a threat so much as a temporary annoyance...once. Basically.
Honestly, I was more creeped out by the Crabsquids, because those boys can show up a lot more places. I tried calling them "Mr Hugs" to make them less scary. It did not work.