Curt was not rational
He did not understand that his attachment to Laurisa was inappropriate, and he viewed the objections as mean and puzzling.
When Linda approached him about it (twice by phone and then by his house), she went on the notion that Curt knew better than to continue his harassment, but Curt didn't perceive his feelings as being wrong, so he reacted by defying the demands to stop. Linda also suggested and offered to connect Curt with a psychiatrist. This shows how strongly she believed Curt was deliberately harmful.
People tend to assume that stalkers are aware of how creepy they are. The stalker thinks everyone else is unfair in trying to 'prevent love' .. because in the mind of that stalker, his 'love' is pure and beautiful.
This person is unable to assess the truth of the situation: that following someone, sending unsolicited gifts, trespassing, etc .. is weird and scary, and it has nothing to do with love.