Well previously when stock trades involved exchanging physical certificates, I could imagine that ownership could evaporate if you lost that piece of paper. Or just think about cash: you do lose that ownership when you lose that magical piece of paper. It's a simpler world when what you have physically determines what you own.
People want a just world (imho, n=1, based on all available evidence, etc), recourse, and protections, not a simple world. Interestingly, cash will likely be the last to go in the near future from a “possession of value” as the world goes cashless (although whether this is "good" or "bad" can be argued in another thread).
