There are people that like fast profit, It is not only the newbies even old folks fall to this category too, yea Bitcoin investment is not meant for shorterm purposes because shorterm does not come with the benefits thats accompanied with bitcoin investment, there are old investors that utilizes every opportunity, once they notice any dump they buy, any little appreciation in the price they sell immediately, no doubt buying when Bitcoin price dips is good but that shouold not discourage anyone from buying whenever he or she is ready, investing in Bitcoin is continuous process thats has no limitations whatsoever.
People who like fast profits, they must choose trading. If they invest in Bicoin, it is mostly for a long term holding. However, if people hold Bitcoin for a short term, it can get profits as well. But the profits must be not very significant. If you bought Bitcoin when the price dropped to $60k few weeks ago, you must take profits now. The current price is around $69k - $70k, there should be some profits to take.
So it actually depends on the goal. If the goal is for small profits, holding for a short term is no problem. But if to earn huge profits, you are right that investing in Bitcoin should be for a long term.
Let's not forget that this experts are just making mere prediction, no one can accurately predict the price of Bitcoin, so we shouldnt rely on the experts prediction to finalize where Bitcoin price will end this year because volatile assets doesn't have a definite price, changes are bound to happen and anything is possible at any given time.
We must rely on our own prediction. Sure, experts also can fail in predicting the price. No people can ensure the future price of Bitcoin whether the experts or beginners. Always remember that prediction has no accuracy.