To a certain extent I kind of agree with you, but on the other hand the idea that every character should be assumed heterosexual until proven unquestionably gay bothers me almost as much. I mean, if the same story above was told with Superman and Wonder Woman, there probably wouldn’t be many who would argue against the idea that it was at least within the realm of possibility to interpret their interaction as indicative of some less-than-platonic motivation. Even if the primary message of the story was still the overpowering strength of their friendship.
And to me, I guess the implication of the possibility for sexual/romantic interpretation doesn't necessarily poison the idea of platonic friendship for me. Especially in this kind of context, I sort of them as two co-existing possibilities rather than irreconcilable separate realities.