I don’t know if it was translation issue or Oda never explained what he actually meant properly. Sommers powers don’t have anything to do with Love. They aren’t like Boa’s fruit that reacts to people’s emotions.
when Sommers was saying his thorns damage you more the more you love his hostage, he means people who love the hostage will damage themselves more on his thorns to try and save the hostages.
when Sommers was saying his thorns damage you more the more you love his hostage, he means people who love the hostage will damage themselves more on his thorns to try and save the hostages.