Really the law's going to have to adapt here if people are ever going to use crypto as an actual currency. Owing capital gains every time you order a latte is nuts.
PS: Trading cars with someone counts as 2 sales, assuming the titles change hands.
If people were attempting to propose improvements via forking and this were true, would that not create rather dire tax liabilities?
Say you bought into bitcoin 'original', and then it forks into bitcoin 'improved' as well. Loads of people agree that the improved version is much better and switch to it, leaving the original near worthless.
But then if this interpretation of tax rules were true you'd be left paying cap gains on the full value of the improved version, rather than the difference between original and improved at sale time. Ouch.