It's not the distractions per se, it's the mental state.

Distractions exist at work too, but when everyone around you is working, you can't help but work as well.

When you're home, your mental state it's "I'm home, I should not be doing work". At least that's how it was for me.

I can be productive working on a personal project when I'm home, but that's because I can work on it whenever and however I want. I can work in bursts of energy. But that's not how professional work is done.