Personally, I'm probably a bit more forgiving than Gomi is regarding this sort of thing (though I'm not sure why I should be) - if you can assert that a particular controversy is
essential, i.e., essential to people's understanding of the subject, then even if that subject is a (preferably deceased) individual then IMO you can make a case for including it. But if the controversy is peripheral, tangential, or otherwise non-essential, it shouldn't be in an encyclopedia - that stuff should be reserved for specialty books and such.
In the cases of, say, Richard II, Alexander the Great, or Hitler, I'd say their sexuality probably is essential, at least for a paragraph or two. Then you have people like the Marquis de Sade,
John Wilmot, 2nd Earl of Rochester (T-H-L-K-D), or Giacomo Casanova, known primarily for their sex lives, and maybe even Wilt Chamberlain, who may have completely changed the way history will view him by claiming to have slept with something like 20-30,000 women.
But as for Baden-Powell, probably not - it's just not generally-accepted enough, and IMO Baden-Powell isn't an important-enough figure historically to deserve having scandalous sex-related info deemed essential. (Not yet, anyway.)
This is an obvious case regardless - the article only exists because Haiduc couldn't get the section he wanted into the main article, so isn't this a clear violation of
WP:COATRACK?