As an airbnb host, I ask for my guests full name and ID *after* they book (I see no reason to ask for that before). Background check is through the platform works fine as well. Sometimes you just need to be open to who is coming (say, in the case of someone new in the platform). Usually things turn out fine! We are constantly being reminded of bad situations through the media, but I believe it is a tiny fraction of guests that can be really problematic.
As a guest (yes, I'm both), I just booked a place where the host asked for my ID and address AND social media (instagram and facebook). I honestly felt harassed and questioned him. Plus, he contacted me through whatsapp (against Airbnb's instructions) and after insisting on these info, I asked him to reply to me through Airbnb platform. He must've checked that it is not okay to insist on those because now he is fine with the info I sent him.
I even feel a bit too shy to ask my guests their full names and IDs (but when I ask for that I remember that is a business reason)... I never thought I'd have a host that would ask for my instagram account! This is why I feel that is extremely important to be a guest when you're a host; there's nothing like putting yourself on other people's shoes.