Investing for the short term or long term is actually fine for any investor because the goal is still to seek profit, and each investor has their own goals and targets.
That's the problem with new investors, they think about profit in the beginning of their bitcoin investment which is the main reason why they fail to hodli and build their bitcoin investment for the future. A new investor should focus more on accumulating bitcoin for a long-term like 4-10 years and above. He should have a bitcoin target which he plans to accumulate and focus on buying regularly with DCA provided his discretionary income is available without thinking of selling a dime.
If the price rises 10%, selling it won't be a problem they just don't want the much larger profits that can be achieved by holding it for the long term.
This is trading and not investing. If you are after profit and sell whenever, you see little profit you will lose the focus of investing for the future and buy as many bitcoin as possible and hodli for long. You will also miss out in the compounding value of your portfolio and will end up with very little bitcoin in future. Long term investment mindset is what every bitcoin investor should plan for because bitcoin is more than what you think it is now.