You can apply any method you consider suitable for you to purchase bitcoin so I disagree with you that one should not buy in lumps. Lump sum buying has its advantage too so should not be completely condemned. No doubt you seems to cherish continuous buying method such as the DCA method which is also a great approach as I do use same but there are instance when I do consider lump sum buy especially when market have crashed seriously thereby leaving us with a good opportunity to buy at lower prices. With extra allocations, one can buy using the lump sum method in that situation and will be realize more bitcoin than someone using the DCA method when the drop in price did not take long to start recovering.
I must also clarify that buying using the lump sum method in the form of buying the dip does not mean searching for the bottom because no one can accurately determine the bottom. It simply involved getting some orders filled when there is deep correction in the market to take advantage of such correction
No strategy is bad for investment if you know how to use it properly. For example, buying dips. If you can buy a bunch of dips correctly, then of course there is no harm in it, but rather there is profit. If you do not know how to use the strategies correctly, then the DCA strategy, which is preferred by most people, can also be a cause of loss for you. The DCA strategy is given the highest priority in investment because this method is easy to use and allows continuous entry into the market and helps to grow your portfolio quickly through continuous purchases. Even in the DCA strategy, you can determine the amount and time of investment depending on your position. Unlike the dip strategy or a bunch of strategies, you do not have to analyze the market too much and do not have to face complex steps.
From a strategic point of view, the DCA strategy is very effective, simple and low-risk, so most people prefer DCA. Therefore, we cannot promote other strategies negatively. If you are educated about investing and are able to use the strategies correctly, you can certainly work to grow your portfolio quickly by practicing other strategies in addition to DCA.