Because EPA chief Scott Pruitt is likely to do something like this (boldface mine):
John F. Kelly, the White House chief of staff, has killed an effort by the head of the Environmental Protection Agency to stage public debates challenging climate change science, according to three people familiar with the deliberations, thwarting a plan that had intrigued President Trump even as it set off alarm bells among his top advisers.
The idea of publicly critiquing climate change on the national stage has been a notable theme for Scott Pruitt, the administrator of the E.P.A. For nearly a year he has championed the notion of holding military-style exercises known as red team, blue team debates, possibly to be broadcast live, to question the validity of climate change.
Mr. Pruitt has spoken personally with Mr. Trump about the idea, and the president expressed enthusiasm for it, according to people familiar with the conversations.
But the plan encountered widespread resistance within the administration from Mr. Kelly and other top officials, who regarded it as ill-conceived and politically risky, and when Mr. Pruitt sought to announce it last fall, they weighed in to stop him. At a mid-December meeting set up by Mr. Kelly’s deputy, Rick Dearborn, to discuss the plan, Mr. Dearborn made it clear that his boss considered the idea “dead,” and not to be discussed further, according to people familiar with the meeting. All spoke on the condition of anonymity in order to describe internal White House deliberations and meetings.
During that meeting, according to two attendees and a third person briefed on the discussion, administration officials and White House aides were in agreement that Mr. Pruitt’s idea was unwise. Their main concern was that a public debate on science — particularly on an issue as politically charged as the warming of the planet — could become a damaging spectacle, creating an unnecessary distraction from the steps the administration has taken to slash environmental regulations enacted by former President Barack Obama.