Ashton was criticised for using the celebration when he opened the scoring in Saracens' recent 17-15 victory against Ulster.
"I think he should do it," the 46-year-old is quoted as saying by ESPN. "He's not doing it to wind anybody up, he's doing it as a moment of happiness. He loves scoring tries.
"For not one person to say last week's try was a world-class finish was pathetic. It was a magnificent try and he took it brilliantly.
"The crowd were on his back anyway. He's never dropped one and I've got no idea why it causes the upset that it does."
Saracens take on Northampton Saints later today in a battle between the top two in the Aviva Premiership.