Olivier Gers was responding to criticism from Britain's Paula Radcliffe, the women's marathon world record holder, who stands to lose her place in the record books if the root-and- branch idea goes ahead.
"I am not sure what's cowardly about this," said Gers, chief executive of the International Association of Athletics Federations (IAAF).
"It's a sad reality of our sport that we are doubting some records.
"What it allows us is to reset the bar. It's a very difficult decision."
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Radcliffe, who ran a record time of 2hr 15min 25sec in 2003, has slammed the idea from European Athletics as administrators of the scandal-ridden sport try to make a clean break from previous doping scandals.
The 43-year-old Radcliffe, a British long-distance running icon, said in a statement on May 1 that the proposal was not only "cowardly" but could "damage her reputation and dignity".
Gers was speaking in Qatar ahead of this season's athletics curtain-raiser, the opening Diamond League event of the season in Doha on Friday.
One of the potential main beneficiaries from any change -- the womens' Olympic 100m and 200m champion, Jamaica's Elaine Thompson -- advocated a mixed approach.
The world records in both of her events were set by America's Florence Griffiths-Joyner back in 1988.
"Those records were set before I was even born.
"My view is I think the cheated ones can go but the ones done fairly can naturally stay," said Thompson, 24.
Thompson's best time of 10.70sec in the 100m trails behind the 10.49sec set by Joyner almost 30 years ago.
"Flo-Jo's" husband, Al Joyner, has already said any attempts to remove the records would "dishonour" his family.
Despite suspicions there was never any proof of doping by Flo-Jo, who died in 1998.
Thompson's sprint compatriot Asafa Powell -- who held the 100 metres world record between 2005 and 2008 -- backed the proposal.
"I hope I don't get into trouble for this but I think they should (go). I agree with it."
However, veteran Kim Collins, who won the 100m world championship in 2003, advocated no change.
"These things happen in history and to change this, that requires changing a lot of history," he said.
The plan will be put forward to the council meeting of the IAAF in August, though it is not yet known when any final decision will be made.