Sorry just had the time now to write a proper reply because I think it's good to be able to have a discussion about this.
Though honestly, just as I can't know for sure what happened, you and other people just creating narratives of what disaster could have happened in his life also can't. For all we know something serious and terrible could have happened. Or he could just have decided he got enough money and didn't care enough to continue the game. It was wrong for me to jump to conclusions but I don't see the point of creating hypothesis and sob stories to jusfity him either.
There's a big difference between our reactions. Your reaction (anger) was under assumption that they ran away with the money. My reaction (neutral) was not based on the disaster. Because we have no idea what really happened, I chose not to have a strong reaction either positive or negative. I didn't defend the creator. I was simply against saying "F you" to them when I didn't know the reason they stopped the project.
Regardless of how justified one's reason to walk out may be, I still don't want to give money to a game dev who won't even finish the game I'm supporting them for.
And you're well within your rights to do so. You are free to choose who to support and why. However, if you're looking at patreon, you might be at the wrong platform because patreon is pretty much for an on-going support that is mostly for an on-going project with no guarantee that it'd ever get completed. So if you're donating with the expectation to get something more than your tier-reward, that's probably a case of you wanting more than what they offer which could lead to your disappointment.
And I really don't like this mentality of people not needing to have responsabilities just because it's Patreon (or other similar donation service)
I think you misunderstand what I'm saying. I'm not saying content creator not needing to have responsibilities. They still have responsibilities to produce what they said they would. But you need to understand that their responsibilities are pretty much tied to the monthly goals and that's about it.
For example, if a game dev said they'd release an update every month, that means their responsibility is simply to produce that. If the game went from 0.2 to 0.7 (0.1 is the free demo), and the project has gone for 6 months, that means they've fulfilled their responsibilities of releasing an update every month. Their responsibility is on month by month basis. If they quit before it is completed, they still have fulfilled their responsibilities up to that point. And because they cancelled the patreon page (which means patrons don't get charged for next month), there is no longer transaction between the patron and the creator.
As I've mentioned earlier, what you're expecting is more for Kickstarter. Kickstarter is different than Patreon because Kickstarter calculated the amount of money needed to complete the project and it only started work if that target is reached. Therefore, the transaction is "Backers giving money to fund the completion of the game". So once the fund is raised, it is the developer's responsibility to complete the game. If they didn't complete the game despite reaching the target goal, then I'd support you to say "F you" to them.