I'm not sure shrewd investors will agree with you on that. Nothing says investors won't want to get more out of their investment by buying low if they know how to get in at a discount. Nobody likes to throw away money in their right senses. Unfortunately, most investors aren't given to analysing the market to monitor price levels. All they want is put money into projects they fancy, buy and hodl for price to appreciate.
You must be talking about individual investors, right? If so, yes, this is true in most cases. But most individual investors fall into the FOMO traps, so they don't buy more at discounts, but when the prices are suddenly moving higher.
But for institutional investors, it's massively different because they invest clients' money and there are rules. In this case, they are obliged to choose wisely and protect the money.