Piracy has become to unsuccessful media what the Chupacabra is to lost sheep - an easy way to both absolve yourself of any responsibility for your failures while simultaneously bolstering an overarching narrative that is either overblown or completely untrue. I mean, there are many things that could cause some project to fail, and even multiple definitions of failure, but it's just so much easier to simply say "because piracy" and skip the whole introspective post-mortem process.
A commercial entertainment product can fail for a number of related reasons, and some of them can happen simultaneously. It could have been marketed incorrectly, or have appeared at a bad time in the market, or it could have been made with no effort, or even just be downright too confusing. It could even be a failure only in the narrow viewpoint of money: a film could be a spectacular hit but wind up being a monetary flop, simply because the budget exploded or it spent too much time in development hell. The mass-culture biz is funny like that.
When you say that piracy killed your movie, you are basically saying that you produced something with high critical acclaim, that had mass-market appeal, but that a large number of people decided to watch without paying. No evidence is given to support such claims, and on the contrary, when someone does cite the piracy excuse, it's usually for a niche game or a bad movie nobody wanted to see. I mean, while the content industry is still scared out of it's wits over piracy, they usually don't complain about it if the underlying work was still monetarily successful. How often do you hear a big CEO say "We made ten bajillion dollars, but it failed because piracy"? Not too often.
On the other hand, piracy is a percieved existential threat by everybody in the content industry. It's not even the fear of reduced revenue - it's the fear that control will be lost. So much of this industry relies not on simple product revenue, or even revenue from international distribution, but on licensing funds. In some corners of the industry, projects will be outright cancelled if they can't get a toy deal. (The animation industry - both Japanese and Western - do this.) So from the point of view of an industry insider, who presumably did everything they could to make a success, it had to be piracy.
The alternative would be to admit fault. But there's problems with that. First off, that requires introspection, humility, and courage in order to do so. And let's face it - nobody who owns or runs a media company has any clue what those words even mean. They all come from very wealthy backgrounds and are soaked in harmful, toxic priviledge. And when people have priviledge, it causes a number of very specific neurological changes. Your sense of empathy dulls, for example. You are essentially blinded to the consequences of your own actions. And that is exactly what happens when, devoid of any other excuses, someone blames the techno-Chupacabra.