Using TOR doesn't mean you are doing something illegal, it is just a technology that protect your privacy. Regarding vulnerability, it is just like having multiple domain for the same site.
Very true. But I keep seeing the ideas "Why do you want to hide your IP if you are not doing something bad? Why do you want to use a mixer if you are not doing something bad? Why don't you want to do ID verification on exchange if you are not doing something bad?". It seems to me that a large proportion of people are having this kind of ideas.