This is like asking why people choose Coke over Pepsi; they're both satisfying and sweet fizzy beverages, and they both can hurt you the more you're exposed to them. Much of people's preferences for one or the other can be written off as frequency bias. Many of us in the industry have scar tissue from battles with both.
Fair question. My motivation was mainly to understand if there was something specific that drove that choice. Better question for you maybe: For any new project, which one would you choose and why?
Since I'm not starting a new major project, it's a pointless question to ask as I'm not going to research what I should use. But you completely ignored my question, why do you choose Postgres?