Tilt would seem to be poker slang for a lack of emotional control. It’s not just limited to entitlement, but can refer to any condition where a player is apt to take unwarranted risks. This site defines it as:
Tilt in poker occurs when you are unable to make rational decisions at the poker table because your emotional state has gotten the better of you. Perhaps you are angry at a bad beat, terrified because you just bought in with this month’s rent money, or got a promotion at work and feel like taking it easy on the table.
Wikipedia also has an entry, but it’s rather poorly written.
Tilt is in Green’s Dictionary of Slang where Green defines it as to raise the bet. The one citation is from Ring Lardner’s 1915 short story Alibi Ike, where Ike accidentally puts two dollars in the pot instead of one:
“Takeout a buck if you didn’t mean to tilt her,” says Carey.
“No,” says Ike, “I’ll leave it go.”
It’s used elsewhere in the story:
They was another pot that he come into with tens and fours. It was tilted a couple o’ times and two o’ the strong fellas drawed ahead of Ike.
It’s easy to see how tilt could shift from raising the bet to raising the bet on a bad hand to loss of emotional control.
I haven’t heard the term before, but I’m not a poker player.