I completely agree with you. Gambling is an individual choice and with it comes individual responsibility for the outcomes. Its all too common for people to seek someone else to blame when things don't go their way. While shifting blame might offer temporary relief it doesn't change the reality of the situation. Recognizing and accepting the results of one's actions is not only part of gambling but a fundamental aspect of mature behavior.
Taking responsibility of your gambling habit is something that every gambler should so without having to be told because gambling is personal and a choice for your own way of entertainment or earnings depending on what you wish to do with your gambling habit but then making sure to take responsibility is very paramount. Blaming anyone at any point for your losses in gamble is sounding irresponsible to me because you took the decision regardless of any influence such person whom you are blaming had on you as at the time of gambling, gamble for fun and not to have to push blames around, how about when it goes your way would you remember to appreciate the person who introduced you if not then always making sure to take responsibility is important.
Just like you did mentioned it actually changes nothing if you push blames around because that wouldn't stop the money from been lost or neither is the casino going to make refunds so it's to accept take responsibility and moved on probably hope to win some other day and recover.