This is another one of those cases where you live in a different version of reality than I do.
First, Masters was AWFUL. God AWFUL. In the ring and on the mic. Just a total botchfest.
Secondly, he was nowhere near over. He was given months and months of time with the Masterlock challenge, was put into a program with HBK and Cena off the bat, and yet everytime he talked the crowd completely turned on him. He got X-Pac heat. The only person who was less over than him at the time was Rob Conway.
I have no idea what you were watching if you thought he was 'fairly over'
He wasn't getting booed as a heel. People wanted him off TV.