That should be true, but I think some investors who intend to hold Bitcoin in the long term also often look at Bitcoin price movements to be able to enter at the lowest price to get the best price so they can accumulate more Bitcoin.
Waiting for price to drop before you buy is not an effective and recommended way of going about investing in Bitcoin because that could lead to a lot of problems for you. First you may never know where the bottom is since the price fluctuates so much, hence you will end up in confusion on which low to buy and eventually end up not buying. Secondly, if price refuses to drop within the time you have the funds to invest and you increase the waiting time, there is high chance that you might use the money for another thing that is not Bitcoin investment, you know how money is and how easily you can spend it. This is why it is better to adopt a continuous buying method like the DCA that does not care about the price but only focused in buying Bitcoin weekly or monthly as it will be convenient for the investor.
Never effective for someone that claims to be a long-term holder, It hinder lots of opportunities, lots of chances to boost your portfolio, since Bitcoin is volatile it's best to approach it with a strategy like the DCA, with that you don't have to wait before buying with the way bitcoin is going it might likely not dip to the point those who wait are expecting so instead of following that path it's better to buy periodically which offers more effective way of building a portfolio.
While some people think it's best to wait, those who understand better what investing on Bitcoin is all about would be gradually building and getting profits on the long run as the price increases, every true investor know the best approach to a better accumulation it's only those ignorant to what the DCA is all about that ignores it.