Not sure who you mean by "the Jersey fishermen" ? Do you mean the majority of them as represented by the president of the Jersey Fishermans Association or the individual, who is clearly anti-Tory, anti-Brexit, anti-democratic, but has an active Twatter account ?
The licences were lawfully issued to those who could comply with the lawful conditions attached to them. Others were not issued as the boats can't comply with the conditions. That will reduce the number of French fisherman who can fish there, which is the whole point, in order to preserve stocks and make the industry sustainable. The point is we are no longer part of the CFP so its up to us or Jersey to issue them however we/they see fit. Some will benefit, some will lose but as long as its lawful then that's how democracy works.
In my opinion the rights and wrongs of these decisions are irrelevant, as long as they comply with the rules and laws which govern them.
What is indisputably wrong is the idea that because a decision or a law doesn't suit you, its ok for you to make threats, illegally block ports, and threaten to breach a lawfully binding contract to supply electricity in order to force through your view.
That's not democracy. That's bordering on anarchy, or dictatorship if it's backed by a government.