I think some people genuinely are nice and good, and I'm thinking of empathic friends who are nice but also honest and genuine. They're out there... and in the minority.
People-pleasers are often doing it subconsciously. But yes, some people intentionally play a "nice" person--especially narcissists and sociopaths--to manipulate you and lure you into a false sense of security.
Some people are indeed fake.
This Mike sounds like a manipulative misogynist who lures women with fake niceness because he wants to use them. After the 2016 election, I realized that an awful lot of cishet men don't see women as fully human.
And... you gave me an idea for a Medium essay. Thanks!