there is another important difference between what you point out and selebus' work. People aren't stealing his product, they're stealing his monthly early access to it, he himself gives away his product for free each month, just a bit later.
From that point of view, it's even more pointless to combat piracy, since you're not even struggling against people taking your precious product for free, just the notion that they're taking away the privilege of those that support you. So, really, everyone that "steals" his early access pass each month is still a potential supporter for years to come, since, again, it's a month to month deal.
To the point, it's far more damning to alienate piracy users in his case because you're also alienating potential supporters. His is not a finished product, it is far more important to create a vocal supportive community (paying or not) than to combat piracy (pointless since it won't yield anything anyway). And even if most of these people never support him, I can safely guess that a lot of them would be willing to pay for the final product after so many years. The only reason why they might not be is because of Selebus' behavior tbh.