You are absolutely right, any investor who wants a huge return must or should accumulate Bitcoin and hold for a long period of time unless they don't want a huge return and then, they can go ahead with the short term investment and whether short or long term there is going to be a return but there will be difference in the return.
Your profitability in bitcoin investment as a long term investor also depends on the size of your investment and not just how long alone. I think both works together. As your aim is targeted towards the long term, your bitcoin holding size should also be increasing over the years. Another thing is that our investment in bitcoin does not guarantee us any returns. In as much as we are expected to see more of an upward trends in bitcoin market as the years goes by, that doesn't mean that we are guaranteed of see any huge return on investment. There may be returns or there maybe not. So using that word huge return sounded like your speaking with certainty that there must be returns and that's wrong.