Airplane's fault???
No, it's the decisionmaker who decides not to pressurize the cabin to the proper altitude.
As for personal responsibility, if you ordered single mixed drinks and the server intentionally increased the alcohol exponentially without informing you (alcohol affects you worse and faster at high altitudes), that responsibility is on the server and the establishment, not the recipient.
https://cyalcohol.com/article/does-alcohol-hit-you-faster-at-higher-altitudes
responsibility is on the server and the establishment, not the recipient.
This is where we disagree. I agree that the server should not “over serve” as a matter of the profession. But ultimately it is the responsibility of the drinker to not “over drink”.