I think of buying UVXY like going to the emergency room knowing that you'll be charged a 1000% sin tax just for walking through the door vs. waiting until the next day to see a doctor. Just like alot of people go to the ER thinking they have an emergency, but find out it's no big deal, investors make that same mistake with the VIX all the time.
When the $VIX is in backwardation, investors see enough of an emergency to pay a premium for immediate protection. Backwardation is rare and doesn't usually last very long. Contango is the norm, meaning investors may buy protection for next month or beyond, but they won't pay the premium for this month because they don't see an immediate need.
The $VIX is in backwardation right now, but the market isn't really selling off in a hurry. So we're basically sitting in the ER waiting to find out if our emergency is real or imagined. If it's real, that's money well spent, and may possibly save our portfolio, but if it's imagined, we'll leave with a huge bill and the memory of a bad experience.