The former Mis-Teeq singer announced her signing to the ITV1 show mere hours after her departure from the Strictly panel was confirmed on January 2.
Subsequent reports suggested that she was lured away after being promised triple her £100,000 Strictly fee, but Dixon insisted at the Manchester launch of Britain's Got Talent yesterday (January 20) that money had "never been a factor".
"If it was, I'd have done so many crazy things over the years," The Mirror quotes her as saying. "I make decisions on what feels right and what excites me.
"I was going to leave Strictly anyway. Three years was respectable. It was time to move on. I wanted to do something fresh - I don't want to be boxed in. I want to try new things. You only get one life, it's not a rehearsal."
Dixon proceeded to predict that she would be an "opinionated" but encouraging influence on the Britain's Got Talent panel.
"Simon Cowell likes the fact I am gobby, but I'm trying to not be so gobby in my 30s," she said. "I am trying to be more eloquent. But I am opinionated.
"I can't be mean for the sake of it. If someone is blatantly rubbish and is trying it on to use their five minutes of fame, then I'd be more impatient. But I want to find someone to make the country proud."
Cowell admitted yesterday that poaching Dixon for Britain's Got Talent was meant as a dig at Strictly broadcaster the BBC.
Watch the Britain's Got Talent stars talk to Digital Spy below: