The 'agencies' are trying to protect their turf, their budgets and their egos.  

Their 'job' is to provide accurate and unbiased intelligence to the Commander-in-Chief in the format which he prefers.  

He, as the Commander-in-Chief, has absolutely no responsibility to keep any of them in their current jobs  or to believe them or to rely on them.  

 "Intelligence" does not necessarily equal "Truth".

"Sen. Ron Wyden (D-Ore.), who repeatedly clashed with Clapper on the Senate Intelligence Committee, scolded the outgoing intelligence official, accusing him of repeatedly misleading the American people and lying to Congress"

“During Director Clapper’s tenure, senior intelligence officials engaged in a deception spree regarding mass surveillance,” said Wyden, a champion of civil liberties advocates. “Top officials, officials who reported to Director Clapper, repeatedly misled the American people and even lied to them.”

November 17, 2016