This is SUCH a common thing, it’s unreal. So many people have said they went into Voltron thinking K/ance was certainly going to be canon based on how the fandom treated it, only to discover “uhh are we watching the same show?” Really interesting phenomena
This has always happened in fandom. 99% of the times when people have pitched their fave show to me because it’s sooooooo shippy, when I watch it the two characters barely even interact. Or their incredibly shippy interaction is, like, standing in the same room sometimes. Or it’s the same kind of relationship they both have with other people, just prettier.
What is new is the widespread sense of raging entitlement that makes people think it’s okay to demand their headcanon becomes real and trash talk the showrunners when it turns out that surprise! it doesn’t.
The only ships I saw canon evidence for in Voltron are Allura with Lance or Lotor. Sheith reads to me as a mentorship relationship, and Klance as two guys who just plain don’t like each other but are slowly getting a grudging respect for each other.