Suter hit took away some of his quickness I thought. The 1991 Canada Cup was the last time that I could see Gretzky being described as "quick" to an extent. Watch his highlights in the 1991 season, he has times where he is like a waterbug out there. Not blinding speed of course, because he never had that, but quick and shifty and unpredictable and mysterious. He always had the last two and that's why he was still good after the Suter hit, but he lost some of his quickness.
I don't know if we can blame Janet for much though. She was a popular target at one point but I think the whole "Yoko Ono" thing wore off eventually with people. She was not a big movie star, and after her and Wayne got married she was basically barefoot and pregnant. So I don't think this idea that his wife lured him to Hollywood ever had any bearing.