Yeah, the leeway given to foreigners can go a long way in these feelings. As a foreigner, you aren't expected (practically not even allowed in many contexts) to ever be a part of the in group in Japanese culture, no matter how many years you spend there. Therefore, one could theoretically be seen as weird as an LGBTQ person, but still otherwise be welcomed as much as one can be as a foreigner. Whereas a native born Japanese LGBTQ person would be shunned and ostracized.

And yeah, it's also a very different scenario and culture being involved in the differences. The weight of something in one culture (ie, being considered weird for something) can have very different connotations in different cultures (can vary in how alienated you are in US culture due to individualistic nature of said culture as well as varying attitudes in areas across the country - but can lead to some very serious problems in a group-centered culture such as Japan's if one isn't like the rest of the group). Both attitudes toward someone of a different sexual orientation are shitty, but in vastly different ways between the cultural contexts.