This depends on the type of person you are and what you’re looking for from your jacket. If you have a couple of dozen pockets and you have a plan for them all then great, that will suit you and you’re style of fishing and you should be put off by wearing a jacket with a lot of pockets.
If you’re the type of person who likes to keep things a bit more simple, however, then having a large number of pockets would probably be confusing and would lead you to having to search around for a long time in order to find what you were looking for.
You need the right amount of pockets for your own style so if you’re the type of person who generally uses four pockets then make sure that you get a jacket with four or five pockets. There is also another consideration of waterproofing and zip failure. The more pockets that you have, the more chance you have of something going wrong.