I think most of us subscribe to buy and hold, so I don't think anyone needs to eat crow if/when others successfully time the market. At one point, I did think the tone of the thread veered towards mockery and I don't think that's necessary or productive, but I confess that I haven't reread it and I recognize that there's no good way to reliably read the tone of anyone's comment here. So perhaps I'm wrong.
The market will dive. It is cyclical and, given the record highs, economic indicators, trade war, etc., it very well may happen this year. You can weather it and anticipate that it will recover in time, you can risk trying to time it, or you can follow some other strategy in between. Who comes out on top 1, 2, 3, or 4 years from now is anybody's guess. Ten to 20 years from now, it's a fairly safe bet that the buy-and-hold and dollar-cost averaging crowd will be more than fine. I've been doing that for 20 years and have saved $1.2M on a non-profit (10 years) and government salary (10 years).
ETA: VTSAX closed at $68.52. It's getting very close to our case study's break even point. Next week will bring new news, new dips and jumps, and new guesses.