I don't think waiting for the dip before accumulating Bitcoin as a good strategy, for there is no need waiting for the dip before accumulating Bitcoin as it is not necessary or important when buying using DCA method.
For me I see buying only when the market is DIP as trading. With your DCA strategy you can accumulate more Bitcoin regardless of the price either weekly or monthly as the case may be.
Buying only the dip strategy is not only done by the traders, those that has gotten to their maintenance level in their accumulation journey can also adopt the buying the dip strategy as they may not longer need to be buying frequently with the dca strategy but may decide to only be buying the dip comfortably.
but looking from the perspective bitcoin buying a dip in an uptrend seems to be a good idea... I wouldn't give it a trading option only too as its a strategy to buy more with less fund so it's pretty much a good strategy just that the "only" attached is not suitable for beginners who have no reasonable amount yet waiting for dip could just be the most stupid that could be done 
The perfect time to buy more Bitcoin is during the dip, but most times I don't fully agree with anyone who's waiting patiently for the dip. The reason why is that most times we might experience a dip not knowing where we are during the dip period. So, buying the moment you have the money to buy Bitcoin is the best time. One might have the money to buy bitcoin but might be scared to buy Bitcoin because either Bitcoin price is higher or the other, so the person might not buy. Now most people, out of this fear, keep their money and wait. Maybe within a short while, some emergencies might occur and the person will use the money he kept for Bitcoin to do something else.
Once a person has the money to invest (beginner or not), they should go straight ahead and buy the amount they can with the money, then apply the DCAing strategy alone, and it will help the person to achieve a significant amount he didn't expect if only he did it constantly. However, to achieve a big Bitcoin investment, you don't have to stay away from discipline. If you make up your mind to buy some small amount of Bitcoin weekly, or monthly, you should try and continue. Moreover, from my understanding, as long as the investment and DCA method is concerned, I don't see any money as small money, even if it's $10 weekly, if you are disciplined enough to continue constantly without skipping any week in a whole year (52 weeks a year), you will have a good amount of bitcoin from your $10 weekly purchase. What matters in Bitcoin investments is your commitment and the kind of strategies you apply.