I certainly don’t know this particular Mormon. Being a Mormon certainly increases the likelihood that he/she is homophobic, but disliking this (or any) song, in itself, proves nothing.
The song is about betrayal and getting stronger from the betrayal. Most anyone can relate to the lyrics, even find a bit of grit from them. I never liked it much and then got really sick of it when lot's of people would say, "I'm a survivor" to make themselves sound special.
To see homophobia in this song is a verification of what Mark Twain said, "To someone with a hammer everything looks like a nail."
According to Merriam-Webster, homophobia is defined as:
"irrational fear of, aversion to, or discrimination against homosexuality or gay people."
This is a broad brush, leaving little room for people who might just have religious or even biological *beliefs* that are related to a reluctance to accept homosexuality as a normal alternative lifestyle.
In principle, I suppose it is possible to have such beliefs without associated "fear, aversion to, or discrimination against homosexuality" but in reality it seems that such emotions go hand in hand with one's beliefs. As such, I think that the broad definition is quite intentional. The gay community, and its supporters, do not want to leave any logical space for opposing homosexuality in the absence of fear, aversion, or discrimination. That way, any discussion of homosexuality as a lifestyle--pro or con--is subsumed by a connotation that there is no rational ground to object to it, under any circumstances and in any context.
This explains why Richard Dawkins' was ejected from the AHA.
The point you make applies to a broad range of phobias and bigotries. Your point is why I have such issues with wording that groups everyone with one common characteristic into a category that makes them all the same by virtue of that one characteristic when most of them are nothing like each other.
When someone treats me poorly or unfairly I like to first assume that they are jealous of my brilliance :) and it has nothing to do with me being gay. I don't consider myself part of the gay community or any community. Contributes too much to an "us-vs-them" mentality that pervades this country. Of course when they use the "F" word or some other slur that changes the game. My favorite were the housepainters calling us "mariposas" having no idea my Spanish was better than theirs. Thank you mission.
Still unsure what "logical space for opposing homosexuality" might be, but I'm sure it would come down to the definition of the word "logical" in the end. Cuz one man's logic is another man's . . . personal agenda?
One reason I like working with a very diverse group of people ethnically and age-wise is that we see each other as individuals.
Of course grouping yourself together because you have one common cause can be powerful. NRA for instance . . . just saying.