I can understand the urge to explore Serious Issues in fiction, even fanfic. It's just hard to do well, because it requires a solid understanding of the issue in question and the ability to convey it effectively. When it's fic, you've also got to consider how the issue would manifest in the canon setting and how the characters would interact with it. (Because directly transplanting an issue from the author's own corner of 21st-century Earth, and/or using the characters as mouthpieces regardless of their canon characterisation, is a cop-out and invariably bad.) It's not just a fanfic thing, either - look at the comics Linkara covers in PSA Hell, with things like Batman tackling smoking or the advertising mascots of a computer company going after the drug trade.