So ask yourself, what's the point of portals? To traverse great distances in far less time than it takes by boat or walking. Adding a limitation to this especially with something just as time consuming as collecting other resources makes zero sense imo. So you would rather drag out your progress over potentially hours rather than minutes. Ok that's all you if you have the time, patience and actually get satisfaction out of it. To me the devs can make their game far more drawn out with better things to do than resource collecting which gets monotonous after awhile. I can spend 4 hours resource collecting metals or actually progressing further in the game, I choose to use mods, remove said limitation and actually feel like it doesn't take eons to progress. For some it's their cup of tea, for others not so much. All I can say is thank god for mods... Also the encouragement to sail comes from actual exploration, seeings how its the only way to make it to new islands, traveling back and forth by boat to the same place over and over becomes very monotonous over time, but again if that's what your into, by all means enjoy. I'll spend my time playing the game doing better things like building awesome bases, fighting monsters, etc...