O que significa a expressão "someone's heart is in the right place"?

I was watching a sitcom when an intriguing situation was created: There's a man who's trying his best to make his girlfriend forgive him for a couple of stupid things he's done. While talking to a friend of his, he remembers his girlfriend loves surprises and comes up with the idea of secretly arranging a wedding party. The thing is, he hasn't even proposed to her girlfriend yet and decides to do that on the same day as the wedding.

When the day comes and he finally puts his idea into action, his girlfriend can't believe how much of a stupid idea that was. She said she likes surprises, but being surprised by a wedding is nuts. Then she tried to calm herself and recognize the gesture of goodwill of her boyfriend. Here's what she said when everything was settled: I know your heart is in the right place, but you had to ask me first. When someone's heart is in the right place, it means they mean well even though what they did doesn't seem like it. It's like trying to please someone by doing something over the top like secretly throwing a wedding party. The intentions are good, but there's lack of good sense.

You can also use that expression to describe anyone kind that occasionally has bad attitudes. Imagine you have a friend who's very annoying. He has no idea when he's crossing the line or when he's doing something that may be hurting someone else, but you think that he's not actually a bad person; he's just immature. One day somebody tries to speak ill of him, and you defend him by saying: You have to be patient with him sometimes, but his heart is in the right place. That's it for today guys. Take care!