"I don't think it's right that you took that man's zoo... it should've been passed on to 1 of the blood daughters in the family," one Twitter user wrote.
Bob, however, gave the zoo to Steve and Terri as a wedding gift.
Due to the family's rift, the 82-year-old has not visited the zoo for years now, despite it being the location of his son's resting place.
Bob's close friend and biography co-author Amanda French recently spoke to news.com.au about Bob's sorrow when it comes to the current state of his relationship with the wildlife park.
“It’s hard for him not to be able to return to his son’s resting place as you can understand," Amanda told the publication.
"He hasn’t been back to Australia Zoo since the wildlife hospital was launched in 2008. It was supposed to be dedicated to Bob and his late wife Lynne, because that was where Lynne did the bulk of her wildlife work."
Amanda also recently appeared on Hit FM's Stav, Abby & Matt on Tuesday to hit back at Bindi's claims that Bob had returned her gifts.
The co-author confirmed the accusation but explained there was further context that had been omitted.
"The gifts were returned because they were odd," Amanda told the radio hosts. "They're always from Terri Irwin, never from the kids. It doesn't say, 'From Terri, Bindi and Robert'".
WATCH: Bindi dresses her daughter Grace in her first khakis (Story continues after video)
Bob's confidante went on to give an example of one of the "odd" gifts, explaining she witnessed the 82-year-old receive a shower cap on his anniversary, deeming it "really strange".
The former Australia Zoo employee also clarified that the Crocodile Hunter's father had never received any correspondence from Bindi herself, before labelling Bindi's comments "passive aggressive".
"To me, it's a passive aggressive thing to do," Amanda said. "That's my perspective, not Bob's, but it's strange".