The combustible 26-year-old unloaded on the Australian two-time Grand Slam champion after being bundled out of Melbourne Park at the first hurdle.
He alleged there were deep divisions in the Australian men's game.
"It's all Lleyton. I'm going to say it honestly -- no one likes him anymore," said Tomic, who had a car-crash 2018 season and faced a backlash after boasting that "I just count my millions".
"He's just doing the wrong thing. He's playing Davis Cup -- I thought he was retired. You know what I mean?
"He used to hate Tennis Australia. It's weird. And now he loves them. What's happened here?
"But I guess he's using them for other things and resources and ... yep. And it's for his pay cheque, yep."
Tomic, who has long had a fractious relationship with Hewitt and Tennis Australia, claimed that he and countrymen Thanasi Kokkinakis and Nick Kyrgios "don't want to play (Davis Cup) any more because he's ruined the system".
"Go away," he said of Hewitt. "Like, literally. If you've retired, why are you still in tennis?"
Hewitt has received a wildcard into the Australian Open doubles and will partner John-Patrick Smith, while reports last month said he was contemplating playing doubles at the Davis Cup in February against Bosnia and Herzegovina.
The 37-year-old played down Tomic's extraordinary blast as "a bit of a laugh".
"I don't think there's a rift, there's always communication going on between the captain, coaches and the players, and leading into the next tie that will all happen," he told broadcaster Channel Nine.
"I had a bit of a laugh to be honest, especially after (Tomic's) loss last night going in and complaining about a few things, so for me I just laugh it off and move forward.
"I guess the disappointing thing, the Aussies had such a great day yesterday on both the men's and the women's side and it probably got overshadowed by Bernard's comments," he added.
Tomic, who rose to a career-high 17 at his peak, has not played Davis Cup since 2016 and alleged Hewitt "doesn't put the players first".
"He doesn't put Nick first, he doesn't put Kokkinakis first. He only thinks of himself," he said.
Tomic is no stranger to controversy after a series of run-ins with the authorities down the years.
At Wimbledon in 2017, he was fined for claiming he was bored by tennis and had faked an injury. His racquet sponsor dropped him as a result.
Last year he even appeared on Australian reality TV show "I'm a Celebrity... Get Me Out of Here".