Why do people like Trump?

Because his Tweets are intelligent and mature
.
(like his supporters)

They think Trump is speaking for them, whether they are white supremacists or they are the religious right or they are poor whites from the Rust Belt.

They see him and they think, "hey, he's an idiot but he's rich, I'm an idiot too, he'll make me rich."

Charismatic, gets things done, funny, confident, and doesn't back down. Unlike our former mixed-race coward in chief who gave billions to terror states.

he's following the standard script for dishonest populists:  appeal to stupid people by selling them the simple minded "solutions" they most want to believe in, regardless of how divorced from reality their viewpoints actually are

in tv land, and show biz in general, they call it appealing to the lowest common denominator. 

Because he isn't one of the 'good ol' boys' politicians who have nearly ruined us.

What Trump has done in the last 3 years is turn the economy around into the strongest economy the country has seen in the last 15 years at least. He has taken on tough problems other presidents kicked the can down the road on for decades. This includes illegal immigration. It includes trade issues with China as well as issues with them on American intellectual property. He just pushed through a major new US, Canadian, Mexican trade partnership (USMCA), eliminating a number of problems with the old one (NAFTA). He has taken a very visible stance with the pro-life movement. He also talks and behaves like a regular guy and not a politician.

The same reason people like any other president. They agree with his economic plans and social views. That being said, people get too wrapped up with presidents; forgetting that they're simply head of the executive branch with limited power. Basically little more than figureheads. 

The short answer is results for America.