I think you don't comprehend the point at SuperBitMan is trying to make, he is not totally saying that it's not good to wait for a DIP, but he is talking about starters or rather beginners who wants to start investing in bitcoin. Just like the price of bitcoin is now, there are some folks who might want to start investing in bitcoin but may consider the price of bitcoin as high and will want to wait for the price to DIP before they can start accumulating so those are the people that SuperBitMan is talking about and not those who already owns a large amount of bitcoins in the custody and may have been satisfied with the amount they are hodling and ONLY looking for an opportunity to still acquire more when the price DIPs.
In all, whether a beginner or someone who already owns investments in bitcoin, so far as they still find the need to buy more bitcoins, waiting for a DIP may not be necessary and besides with the use of the DCA strategy, they can still meet an opportunity to buy at a DIP price within the intervals of their accumulation stage.
Bitcoin is for the long term investment not for short term. There are people who get excited whenever something goes up whether its stock market or any other trading market. They invest with the mindset that since the market is going up, we can invest our money and take profit in short term.
Today Bitcoin is at it's peak and same people think that it's right time to invest in Bitcoin since it's going up and will profit in short duration. I largely agree with most of what you said here like Bitcoin investment is for long term and I also agree to the fact that most people only invest when the price is going up believing that they can sell for minimal gains along the line, but what I totally disagree with here is the words I made bold in your statement, which you said that Bitcoin is at it peak.
Bro sincerely speaking, Bitcoin is nowhere near it peak price, because we are still in it early days, I believe that with the kind of potential Bitcoin has, it can go as high as a million dollar in the future, so 100k that it is now is nowhere near the potential price of Bitcoin in like 10 to 20 years time from now.
So in my own opinion, now is still the best time to buy Bitcoin regardless of it current price because it can still do like 10x to 20x of it current price in the nearest future.