That's it, Bitcoin is an unstable investment, and no one can predict when the price will fall. Selling a portion of our holdings in order to buy back a dip seems to be predicting that the Bitcoin price will fall more, and no one knows what will happen in the next hours. When we are not in an emergency condition where we have no other options for selling our investment, we should not sell our Bitcoin if we are making a long-term investment. We may sell now and the Bitcoin price continues to rise, so it is better to refuse to sell and continue buying high and selling higher in the future, bright days are on the way.
We don't need to search for the bottom.
We can just buy at the prices till the bottom would be reached, but we don't need to buy in lumps the price that is probably not the smallest one.
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