Misanthrope: Noun
Definition: a person who does not like other people
Source: http://www.merriam-webster.com/dictionary/misanthrope
In the article ” The Happiest and Saddest Places in NYC, According to Tweeter” by Brian Merchant he states ” I can attest that each is capable of turning the gentlest romantic into a misanthrope.”
Now that I understand the word I know the sentences was trying to tell me that even the most lovable person can turn into a antisocial person while visiting those places.