A front-yard garden may be easy to see from the street, but it is still part of someone's home, not a neighborhood produce stand where anybody can wander over, pick whatever looks ripe, and leave a polite little message afterward as if that somehow turns taking into sharing.

Now, this homeowner isn't upset because she hates the idea of giving food away. In fact, she clearly loves it, having grown up in a family where extra tomatoes and peppers were delivered to neighbors and friends were invited to take what they could use once the pantry was stocked. 

So no one can really blame her for not being generous. She just, very understandably, doesn't like being denied the option of choosing to be generous.

The older neighbor down the street decided to create his own arrangement, which is convenient for him because it removes the possibility of hearing no, and the way he just has to wait until the vegetables are grown, then just reach into somebody else's front yard, help himself, and then leave a complimentary Ring doorbell message explaining that he appreciates them, how he only took a little, and left something in return. 

Very considerate, except for the tiny detail that none of this was his decision to make. A thank-you after taking does not become permission simply because it is delivered in a cheerful tone.