Tom Shales of The Washington Post said in a guest posting on critic Roger Ebert's blog he thought ABC was exploiting Roberts' illness to boost the show's ratings.
ABC News Senior Vice President Jeffrey Schneider told TV Newser the coverage was a response to the concern and interest of "GMA" viewers who were following Roberts' battle.
"We are also mindful that Robin derives great strength from the overwhelming outpouring of love," Schneider said. "That Tom wouldn't understand is no surprise around here."
Shales said ABC seemed overly eager to play up Roberts' cancer treatment, with timely press releases and insistence that media outlets credit "GMA" if they wrote about it.
"On every edition of GMA, there are shout-outs, warm wishes and detailed reports pertaining to Roberts' condition," Shales wrote. "She has been seen in remotes from the hospital, and the sympathetic outpourings of viewers have been heavily documented."
"GMA" ratings have improved since Roberts began a medical leave Aug. 31, The Hollywood Reporter said.
Roberts announced in June she had been diagnosed with the blood and bone marrow disease myelodysplastic syndrome.