What my GUE Fundamentals instructor told us was that use of the hands is information -- you are trying to accomplish something when you wave your hands, you just have to figure out what it is and get it done another way. For example, I often watch students pushing upward in the water -- it's a reaction to feeling that they are too light, and they try to push themselves down rather than vent the BC or exhale. Another time I see students using their hands is when they are off balance to one side. This is often a two-sided problem: their BC may not fit well, allowing the tank to slew to one side and put them off balance, and they may have very soft fins that are hard to use for stability. (I detest split fins in OW students for this reason -- even the cheapest plastic paddle fin is better as a stabilizer!)
At any rate, I do not agree with the people who say the habit will go away with more experience. Most likely, it won't -- you will simply ingrain it. Now is the time to get it stopped. Analyzing your equipment for weight and balance (and stability) is one good thing to do. Working on maintaining good, neutral buoyancy is another thing. AND you have to make sure that your hand usage is conscious, and that's what swimming with your hands clasped, or holding onto something (no, I don't recommend a camera until your buoyancy is really solid) can help with. I spent a lot of my early dives holding onto my inflator hose, which was probably done out of nerves, but did have the effect of limited at least the use of THAT hand.