If the two lead characters are male and female, people will ship them just because they're the leads.
If the two lead characters are male and female, some people will ship them just because they're the leads, regardless of whether there's any indication of attraction between them, or how inappropriate it might be. Long-running works may end up being influenced by this, either by attempting a blatant Ship Sinking or by giving up and making the leads an Official Couple. I can see this could have potential to becoming Complaining About Shows You Don't Like and/or Fandoms You Don't Like, so Should We Have This?? Perhaps examples could be limited to well-known and -documented historical cases, such as:
- George Bernard Shaw was so annoyed by people shipping Higgins/Eliza, the two central characters of Pygmalion, that he wrote an essay for inclusion with the published script pointing out in detail why Higgins wouldn't want to marry Eliza, Eliza wouldn't want to marry Higgins, and it would all end if tears if they did.
- In the early years of The X-Files, there was a famous dispute in the fandom about whether Mulder and Scully should have a relationship, which popularized the term "shipping".
Hello, Unknown Troper. You'll need to get known to lend a hand here.