You are absolutely correct and most times what makes some investors to be overly aggressive is because of the market Dip some people use this period to ruin there investment unknowingly because the moment you accumulate or buy more than you are suppose to buy in this period you will definitely see the consequences within a short period of time. Ordinarily Dip is suppose to be an opportunity to increase or double one's portfolio but i don't know why some investors abuse it and sometimes it is been done out of greed or ignorant of the fact of what the outcome will look like.
In addition, buying too aggressively can cause sudden losses, for example if you buy when the price may have dropped and you think it has entered the support point but it turns out there is still a further decline if you buy it too aggressively at the beginning then in the next decline we do not have enough funds to buy more at the lower price so it would be better to buy periodically such as using DCA it will make us more controlled in making long-term investments and we can see the benefits in the existing DCA calculator if the target we have achieved is met.