Setting a boundary about my neighbors using my yard for parking. Should I say something?

I live in a neighborhood where my neighbors host a weekly get-together. For a long time, guests would park all over my front yard. My front yard is gravel, so it looks like an easy place to park, but it's still my property.

After dealing with it for quite a while, I finally told my neighbors that I wasn't comfortable with people parking in my yard anymore. I wasn't rude—I just set a boundary and asked that their guests stop using my property.

Since then, things have changed. They used to be very friendly. Whenever we'd pull up in our boat, they'd ask what we caught, chat with us, wave, etc. Now they've completely stopped talking to us. The last couple of times we've seen them, they've actively avoided eye contact and acted like we don't exist.

I honestly wasn't trying to create drama. I just wanted to have control over my own property. At the same time, I can't help but wonder if I handled it poorly because the relationship seems to have completely changed.

Would you be upset if a neighbor asked you not to use their property for parking? Is this just the natural consequence of setting boundaries, or is there something I could have done differently?

I'm curious how others would view this situation. Should I say something or leave it be? I feel like we are in middle school.