Because they're dishonest creeps who have sucked up to him in the past? Because he can't stand two-faced phoneys who use his name to attract attention and get ratings while they insult him and lie about him?
George Bush didn't let his detractors in the media "get to him." He ignored them, let their lies go unanswered. Where'd that get him?
No, this is deeper than that. He's accused others of fake news and poor journalism without getting as personal as this tweet is. This is visceral hatred and I can't understand why he's letting these two nobodies get to him that badly.