I have no idea whether that's true, but it is not necessary for the comment to say "to each their own" for the commenter to have just been expressing a personal preference. They weren't making an "argument".
Since it seems I wasn't clear, the parent comment we're currently discussing has been considerably modified compared to what it was at first. You're free to disagree, but in my opinion the original tone of their comment very much did make an argument. But I do suppose you could label every comment as just a personal preference, because that's what they are at the end of the day.