Sounds to me those reviews you saw OP were by a very disgruntled "Pet" of some triple "A" title thats never done as well as this on the best day of its life

(Yeah looking at you C.E. - But I digress)

As stated above. No not abandoned at all but the initially tiny team were overwhelmed by the success and have determined rather than cutting and running they will do justice to the game by well done additions not cash cow grab DLC's

So yeah its a bit slower than some would like on "updates" but honestly I find it so re-playable that there isn't gonna be an issue for many a year even if things were to stop.

I suggest You go and buy it and try it and after 1 week(ish) if your not sold on it then you can give your buddies direct one to one feedback. I suspect we'll see you around ;)

Oh and also watch out for sailing too close to unexplored areas... Go cautious and you'll be good!