Tillerson gutted the State Department, not filling vital diplomatic posts, ignoring key adviser, and not spending a single dime of the 120 million allocated to counter foreign interference with our elections. That did not bothered President. What bothered Trump is what follows from
https://uk.news.yahoo.com/five-reasons-why-trump-fired-141033008.html, which all add up to disagreeing with Trump. (Parenthetical comments are mine.)
Numero Uno: Late Monday Tillerson said that while it wasn’t clear “whether it came from Russia with the Russian government's knowledge” that he trusted “the UK's investigation and its assessment that Russia was likely responsible for the nerve agent attack.”
Tillerson’s reponse broke with the White House line, which stopped short of blaming Russia for the attack. Tillerson also told reporters that the attack would “certainly trigger a response.” (It didn't stop short enough for Trump who is overprotective when it comes to his BFF.)
2. Last October Trump challenged his top diplomat to an IQ test after it was reported that Tillerson called him a “moron” after a meeting at the Pentagon. During that meeting Trump had called for an increase in America’s nuclear weapons stockpiles in contravention of international treaties. “I can tell you who is going to win,” the president told Forbes magazine during an interview later. (At least was a good judge of character.)
3. Trump and Tillerson have clashed over the administration’s approach to North Korea and its intensifying nuclear weapons program. Last summer as tensions rose when Kim Jong Un and Trump traded insults, Tillerson said the U.S. wanted to “resolve this through talks,” rather than the military options the White House said were on the table.
Last week Tillerson said that an upcoming meeting between Trump and Kim would focus on “talks” rather than “negotiations.” Yet the president appears to expect a deal with Kim on denuclearization. (The narcissistic self-proclaimed "deal-maker" may just threaten this breakthrough with his boasting.)
4. Trump disagreed with Tillerson’s policy approaches on whether the U.S. should mediate in a dispute between Qatar and Saudi Arabia. The two also disagreed on whether the U.S. should remain part of the Iran deal brokered in 2015 to stop the country’s development of nuclear weapons.
5. Tillerson almost quit in frustration last year, according to reports, after Trump publicly berated Attorney General Jeff Sessions over his decision to step away from the Russia investigation. Several sources told CNN that Tillerson believed it was unprofessional.