I think the introduction of the concept of crack!ship has also changed the way we view fanfic. If I look back 15 years, and wonder how a crack!fic would have been received, I just... can't picture it being appreciated, at all? I feel like people would have been more "shut up and don't waste my time" about it.
Nowadays people have taken the concept to such an extreme that there are fics about inanimate objects having a personality and/or a sexuality and I don't understand if they're just a writing exercise for the person who pens then or even just what kind of satisfaction they can get really, from producing work that is meant to shock/amuse people rather than grip them? I feel people feel a lot freer about shipping pairings that aren't obvious or even shipping crossovers between shows (which I don't like/get). I don't really know why they do it... I'd say "for the attention" but then not everyone produces fan works that they want to claim attention for. It could just be a sense of freedom/liberation "I will ship what I want and you can't stop me". Personally I prefer it when people have at least some sort of supporting argument for their ship - I just seem to value well thought-out explanations even if I don't necessarily agree with them.