No you're right. But you don't have to worry about it. It's rather a good news in fact, I hope it will be enforced heavily.
The idea is that you can be taxed ONLY if you sell the result of the fork. If there is a fork and you don't do anything with the coins then nothing is taxable.
How is it a good news? Well it decreases the incentive of a fork. Because tons of people won't get the new coins, knowing they will be taxed.
Hence less shitcoins and less forks.
I hope you're right but their FAQ says:
If a hard fork is followed by an airdrop and you receive new cryptocurrency, you will have taxable income in the taxable year you receive that cryptocurrency.
So what does receive mean in that sentence? Because I technically could say I have Bitcoin Gold, though I've never downloaded their wallet, nor imported my private keys into it. But I had Bitcoins in actual Bitcoin addresses at the time of the Gold fork. When do/did I "receive" the Bitcoin Gold? Do I already have them? Not until I sell them like you interpret? Do I have to backfile my 2017 taxes if I sell the fork now as income then, plus pay the capital gains? Can I argue at the time of the fork the chain had no value and thus there was no actual income?
It's all so stupid.