The Masters champion was picked out for abuse at Hazeltine after his brother Pete wrote a scathing article criticising the behaviour of American crowds.
His sibling dubbed the home support a “braying mob of imbeciles” ahead of the competition but Willett, 29, was quick to offer an apology.
However, after being subjected to boos and heckles throughout his three days on course, Willett later tweeted to say his brother “was, in fact, correct” after claiming some fans “don’t know when to call it a day”.
Now he says his first taste of Ryder Cup action was spoiled after abuse was even aimed at his family.
Willett, who lost all three of his matches, said: “You’ve got 150-200,000 fans there that love watching golf. Unfortunately you’ve got the odd one or two that don’t actually go there to watch the golf, which is a shame.
“But I don’t think that’s ever going to stop. We got a taste of it last week, being in America with the fans and how they push on to help their team win.
“I think people realise what was said was reflecting on a massively tiny proportion of people that went there.
“That’s just how it is, unfortunately.
“When you’re walking round a golf event week to week, everyone’s fantastic. You pitch up and play a normal golf event anywhere in the world and the fans are great.
“I don’t think you should be walking around playing golf while people are saying things to your parents and saying things to your wife. I don’t think that’s our sport, that’s not what we play for, that’s not what we do.
“Unfortunately that happened and unfortunately it put a little bit of a downer on what was supposed to be my first really good experience of the Ryder Cup.”
Willett raised smiles at the post-tournament press conference when he summed up his debut experience in blunt terms.
“Shit”, he said. “Being honest. Sorry, would you like me to elaborate? Really shit.”
But now he admits he could have chosen his words more carefully, saying: “It’s difficult when you have a press conference straight afterwards, the emotion’s running high. It has sunk in a bit more now.”