To my understanding, Netherlands had a long-standing tradition of maritime commerce. Before discovery of sea routes to Asia and Americas, they were doing a lot of trading within Europe (e.g. selling Polish grain on the Western markets). After the discoveries, it was somewhat natural for them to expand on to new markets. Spanish Jews or French Hugenots (to my knowledge) didn't have much of expertise in terms maritine commerce, so I don't think they were a factor (however, the Jews might have facilitated development of financial markets for financing the overseas trading expeditions).