Well in fact, everyday, bitcoin trades at a lower price and I don't know if you also know that. Also, short-term trades are quite risky on an asset with an upward trend. There's a small window of swings everyday in the market, but that window is minute for inexperienced traders to even bother. While shorting still works, most of the people will just lose money in the process, so for me, a bad advice.
That is what you call faith. Also, looking at the charts you can see that bitcoin always recovers from a downfall for the past 8 years. Would yoi want to look at that as well? And no investment has performed really well in a short span of time (see gold, precious metals and other stocks) unlike bitcoin, so I don't see where your 80% loss of value came from.
Refer to the first quoted post. You encourage to short the market swings, right?