Domains are lke any other piece of rare property.
With the same argument, people speculate on food and let other people die. Just because something is a rare property, it does not mean it is morally acceptable to block it and not even require it or use it. On the contrary.
Scorn, envy and resentment are usually indicators that your domains worth something.
I could not care less about this specific list of domains.
And OP's point that grabbing up Bitcoins for speculation is spot on. Bitcoins, like domain names, are scarce property. If you think they're more valuable than current market rates, you have every right to acquire them, nothing wrong with it at all.
If you've ever filled up your gas tank on a certain day because you thought oil prices were due to rise, you've done exactly the same thing as the domain grabber. All humans speculate, and good thing we do.
Your comparisons are completely off. Bitcoins and oil are interchangeable. Domain name squatting is comparable to getting up early to block the best lounge chairs on the beach, then go home and sleep and decide not to use them at all.