Agreed. The author's interpretation is unconventional. 好きです (suki desu) is clearly closer to the English "I like you" than "I love you" in this context.
Japanese people would be just as put off by someone confessing with the loftier 愛している (ai siteiru) "I love you" as someone saying "I love you" in English.
Japanese people would be just as put off by someone confessing with the loftier 愛している (ai siteiru) "I love you" as someone saying "I love you" in English.