Fair points - and Jellicoe was probably the most capable of the WW1 admirals. But if you read his Grand Fleet Battle Orders, you can see an obvious reason why his captains didn't show much initiative. They're immensely detailed and cover in huge detail what captains should do in every conceivable situation. Captains were probably too busy thumbing through them to find out what to do to start wondering if they should act on their own initiative.Jellicoe commanded a fleet that hadn’t fought a peer in a century, and was adapting to a ferociously rapid technological transformation in all aspects of ship design, guns, shells, and fire control. Plus new threats like mines and torpedoes.
Given all this, plus his status as the one man who could lose the war in an afternoon, he did the professional thing which was to use his fleet cautiously despite the strong aggressive tradition of the RN.
But that lack of initiative was what did for Jellicoe. All some captains needed to do was signal 'enemy sighted' or simply open fire. They just sat there. Jellicoe just didn't have the visibility to see everything. He needed his captains to keep him informed - but he'd stifled their initiative.
To be fair to Jellicoe, he had informed the Admiralty that he intended to use a cautious strategy - and got their approval. So he was acting in accordance with the wishes of his professional masters.