What is even with this mentality? I know about 'girl on girl is hot', but even then, the orientation of the relationship shouldn't say anything about its nature. It's just short-sighted, in my opinion.
I feel the same probably due to me being bisexual, but in the end it's not much of a big deal unless it gets to a point where it flanderizes the characters.
Because it's vitally important to see lips locked on a picture intending to be cute. In fact, some would find the naïveté of covering a kiss with a hat (ala western cartoons and a few Disney movies) to be cute in itself.