That happens when you plan to diversify into bitcoin and altcoin. If you have plans to invest in bitcoin alone you can decide to use to method of investment (long term and short term). By so doing you are not going into any risk cause you take profit from the short term when their is an uprising in the price of bitcoin when the market gets to ATH you also have an added advantage in your long term project because your profit will be coming from both sides. When you diversify into bitcoin and altcoin the risk could give you a little bit of mental imbalance cause when bitcoin is going down the dip your altcoin goes completely done sometimes when bitcoin rises again not all altcoins survives to rise after each dip.
I can invest my money in stocks, gold, real estates that are traditional assets but if I want to diversify my investment, I can consider and choose a new market like cryptocurrency market and pick a best asset there like Bitcoin. If I feel risky with stocks, I can choose only gold and real estates from traditional markets, and choose Bitcoin from cryptocurrency market.
Spending money to altcoins is very risky and it's not like good investment so altcoins are not my choices for my capital investment diversification practice.
Diversification in investments is a very good thing because you do not have to depend on one investment, if one investment loses, there is a possibility of profit in another investment, so we always say that it is good to diversify investments. Those who can afford it should definitely invest in different places instead of investing all their money in one place. But of course we have to invest in the right place after knowing and understanding or research if we do not invest in the right place, the possibility of losing money can increase manifold. I think investing in Altcoins is very risky, all the money can be destroyed at any time as a result of investment.