To clarify, I think Duterte has some of the worst combinations of personality traits in a leader. He seems intolerant, ignorant, mean and arrogant. He seems like a terrible person to be running a country.
On the other hand, I can see why he has popularity in the country - The Philipines has a very serious drug problem, and to the average voter, Duterte's strategy of "Killing all the drug users and vendors in cold blood" seems like a good idea. After all, it's an efficient way of ridding the country of the drug problem, right?
Wrong.
Pretty much all modern research suggest that severe drug problems are a symptom of societal issues. There will undoubtably be reasons why so many people in the Philipines use and sell meth, for example, the main one being that there aren't many other ways of making good money. The leaders of countries need to start tackling the underlying social issues that cause the symptoms of drug addiction, rather than just trying to kill everyone involved. To a lesser extent, the same could be said of Western countries (UK/US etc) than imprison individuals for drug possession (Yeah, they're not killing them, but they are locking them up for victimless crimes).
His tactics have huge problems, one of the most obvious being that innocent people can be shot in cold blood, then framed as drug users (with no real evidence apart from a hand written sign on their corpse telling people they took drugs... yeah sounds legit
). Another problem is that his violent massacre is taking out users as well as dealers.
While I wouldn't even condone the assassination of dealers, assassinating users/addicts just seems like an incredibly fucking medieval thing to be doing in this day and age. Morally, what have these people done wrong? They haven't hurt anyone, stolen anything, yet because they choose to partake in drug use they are sentenced to death? These people need fucking HELP, not to be shot in a motorcycle driveby by a hitman, accepting money indirectly from the government (yes this really is happening, saw a documentary interviewing hitmen/women that were doing exactly this...)
Duterte sounds like he's on the way to becoming another Pol Pot or Hitler, simply dictating his own narrative with a closed mind, and with little empathy or understanding towards the citizens he's killing.