I'm curious why so many people say it like this, even out loud. I also hear it with other objects of love, like "I heart pizza", or "I heart walks in the park".

I'm curious why so many people say it like this, even out loud. I also hear it with other objects of love, like "I heart pizza", or "I heart walks in the park". "I heart something" is so awkward it's like you have to deliberately ignore the obvious reading ("I love") and choose "I heart", maybe to be playful. Meanwhile, "I love something" is as old as English. I saw the logo when I was a child and immediately read it as "I love New York". If it sounds like I'm criticizing you, it's more that I am deeply curious! I feel in the minority, because I hear people pronounce it "heart" more often than "love".