Without copyright people would mangle works beyond recognition from the author's vision, it's an exploitable law but a necessary one. About rights and laws, they don't really happen in nature, they're both enforced by the government, institutions and, on occasion, the common folk and they are necessary to hold people accountable. Laws exist to protect us.
Every non trivial point you make in this post is wrong. Refuting it would require a lot more effort than I'm going to put in.
If i had something against piracy i wouldnt be here, now would i? I believe our lawmakers would actually call it "hacking" because you illicitly gained access to a internal resource? God our lawmakers are stupid. But yeah, its piracy. Like, do you think sending your friend a copy of a drm free game so they can play it without paying (and so on) isnt piracy because theres no drm on it?
And the nerve of if is because doing that and arguing its not piracy would, rightfully, piss off the dev even when they knowingly condone/tolerate that patreon early relases are shared here. Its like posing to nintendo and telling them "whatchu gonn do about it huh". Not gonna have the results anyone would want.
As for the morals of copyright? I dont believe its a natural law, but its a helpful one. Only its been perverted to benefit mostly only the rich, abused to shut down project that they realistically shoud not, only because of the almighty "more dorrah for me". Granting a monopoly for new inventions for 20 years so you can safely make back your investment and some for taking the risk of trying new things, aids innovation., by encouraging people to take that risk. Granting that right for 200+ years? Not anymore, now it just stifles anyone who could be building on top of those ideas. Iteration and extension are important parts to progress and mastery and the current situation kills it.
There are no controls on access to the google drive beyond limitations on where the link to it is released. If you have a link to it, you can access it. I'm pretty sure that the definition of hacking in the US at least requires that the person claiming to be hacked has to have put in some sort of controls on access. Sending a copy to a friend would legally count as a violation of copyright because you don't have permission from the copyright holder to make copies. The Google drive does have permission, so it's probably not a violation of copyright. I also would strongly dispute the idea that copyright is actually helpful. There really isn't any way to support that notion without trying out abolishing copyright for a while to see if things get better or worse. I understand the theory behind why it is supposed to be a good idea, but I think that the reasoning which underpins it is unsound. I mostly agree with the article
You must be registered to see the links
. It's available for free and there is an audio version if you want to listen while you do something, so rather than waste more time arguing I'll just reccomend reading/listening to that.
So such leaks I will attempt to contain not because of piracy, but to not damage the games reputation.
Piracy tends to refer to copyright violations, worrying about reputational damage from inferior products being distributed with your name on them is the purpose of trademark, which is a much more reasonable notion than copyright and it protects the consumer from faulty goods which are misleadingly advertised even more than it protects the trademark holder. I think it might be more accurate to call what you are bothered by bootlegging.
You think people read stuff? I have a bridge to sell you, great offer and you wont find a better deal.
I think there are ways you could make a disclaimer so intrusive and clear that people are unlikely to miss or misunderstand it. I don't know if it's worth the effort to do so right now, but if people keep finding the dev builds and getting a bad impression of the game from them, then it might be worthwhile to do something obnoxious like covering the whole screen with a disclaimer you can't click through and have to type something like "I RECOGNIZE THIS IS AN UNSTABLE TEST BUILD AND I SHOULD BE PLAYING THE STABLE BUILD INSTEAD" to proceed, along with an air raid siren playing in the background or just a recording of you yelling "don't play this version you idiot, play the stable release".