Maybe the risk they are looking for is the volatility aspects of Bitcoin, but people into long term plus executing DCA could really ignore those situations. Because people aims for long term on Bitcoin doesn't really look at the prices since every situation is good opportunity to accumulate whether the market pumps or at the dip.
Although I understand with people saying that they should buy more Bitcoin at that time, but they also need to know that this is not the only option they could do. Since whatever instances comes in the market people can continue to accumulate.
What I like about DCA strategy is it lower down the risk to lose from volatile market.
Don't take volatility of Bitcoin as risk, it's a double edge sword that swings in both directions. It's only because of volatility we are seeing an exponential increase in price of Bitcoin. Bitcoin started it's journey 15 years ago with zero dollar and in 15 years it managed to touch 100k, it's all because of volatility. If there is no volatility in Bitcoin then we can compare Bitcoin with something like money stored in banks or money you invest in government saving schemes, there is no volatility in such schemes but the profit you are getting is very much aligned with inflation rate. Such schemes look profitable but in reality they are not profitable.