Agree with you there. I wanted to post it with clarification before but tried to keep my post to the point.
This part of Quran is taken out of context by some people. I do not have the source at the moment but it has to do with verses before this part also.
Something like when you are on your way to pilgrimage?
Someone can check it.
Bottom line: not everything from sea is halal as universal ruling.
Some hadiths have clarified this issue further.
Will someone eat jellyfish, eel or sea snakes etc? A different issue but karahiat is a valid issue.