I have seen many people who earn bitcoins and manage all their life expenses with it. I agree with you that investment in Bitcoin needs to be long-term. Because it is not possible to extract full profit from Bitcoin if not in long term. According to me, some part can be spent for special needs and the rest is better to invest.
When you earn Bitcoin and use it for your living expenses, that is different from investment which we are discussion here and also different from the long time hodl as well. Assuming such person have a fraction of the earned Bitcoin he is saving regularly, similar to what the DCA method, then it could fit into this discussion. So instead of opening another long chapter in this discussion which will serve as a deviation, we can just focus on how to buy and how to hodl.
Regarding the DCAs strategy have been designed the impact of trading investing, fixed asset remain regular over time. It's have no limited to BTC but it can apply to any others investment.
DCA strategy is is a method of buying bitcoin at a certain intervals on a regular basis and not for trading investing. Don't confuse yourself with this thing. I don't know what you are referring to as fixed asset, but for the purpose of this thread DCA is a method of buying bitcoin. We are not discussing other investment assets here.
His comment is just filled with unnecessary wordings that will end up getting him confused. If I say I know what he is actually driving at, it means I am being economical with the truth. It is good you gave that clarification so that people will not get confused further by his placement of DCA method with trading investing.