The 'Domino' star, who has already confessed to making some contestants cry, claimed that the singers will thank her in the long run.
Responding to claims that she is the "evil" coach, she told The Mirror: "That's good. The contestants have to realise they need to raise their game.
"I'm not saying it's easy - I know how it feels to step out on a stage in front of millions of people I don't know. When I performed on The X Factor last year, I was shaking like a leaf. But it's got to be done and they need to embrace it.
"I feel if I'd auditioned for one of these shows I wouldn't be doing what I'm doing today. You have to go through life's experiences - good or bad - to learn from them."
She also criticised the press for constantly comparing her to other female artists.
"[I'm compared to] Cheryl [Cole], Tulisa [Contostavlos], Nicole Scherzinger, but I'm so bored by it all," she said.
"When Tulisa and I get together we don't talk about X Factor or The Voice, or ratings or tactics. We talk about being young, fake tan and make-up!"
Jessie J recently turned down Simon Cowell's offer to join The X Factor.
The Voice UK continues tonight (April 7) at 7pm on BBC One.
The Voice UK week three: First look pictures
Watch Jessie J in her video for 'Domino' below: