Because slander/libel is considered a remedy against falsehood which threatens or damages an individual or organization or their reputation.
You're still free to speak your mind, but if you can't prove what you say is true, then you're in trouble.
For example, the families in the Sandy Hook incident could sue Jones. Clinton could, as well.
Veteran conspiritard David Icke has long contended that the British royal family are actually 12-foot tall lizard people from outer space, disguised as humans to enslave our race. "If it's not true, why haven't they sued me?" he asks to anybody who questions the notion. Generally, the answer to that is that jumping in the sewer to fight with rats just leaves you smelly and dirty, even if you kill the rats.
In the case of the Sandy Hook families, some of them are suing Jones. His lawyers have alternately argued that his stuff is too silly to be taken seriously, and that suing him would put a chill on journalism. At one point they even compared him to Woodward and Bernstein. Whatever the case, these families might get some cash from him, but they won't get their lives back: they'll continue to be harassed by demented Jones listeners who are still convinced it's the truth regardless of the outcome of the lawsuit.
In the case of the pizza shop, Hillary didn't file a lawsuit against Jones, but the pizza shop did, after a deranged idiot showed up with a gun demanding to "free the children". Jones begrudgingly issued a retraction of his Comet Pizza theories to avoid being sued, but this doesn't really make up for the fact that, you know, a deranged idiot with a gun showed up at their store and threatened people. Thankfully nobody was hurt, but it could have easily turn out differently.
And what if there's nobody to sue? At present there are more Comet Pizza style fake news items being circulated around, but instead of Alex Jones they're being put forward by "QAnon" and anonymous pranksters on 4chan and that sort of thing, and being circulated around Twitter and Facebook by morons, crazy-people, and gullible old-people. Who would you sue? Where would you even start? If they do track one of these malicious lies to some basement-dwelling, child-
**** obsessed incel teenager and sue him, is getting $13.52 from his broke worthless ass going to make up for the damage done to your business?
I think the worry is bias. In one of the things I read, and maybe posted recently there was a thing about a reporter for the New York Times who regularly tweeted things about whites which were pretty racist, although now she says, basically "I was joking!" If so she liked to joke like that over a long period of time. Someone retweeted her exact words but reversed the races and twitter blocked them almost immediately.
https://www.instyle.com/news/why-new-york-times-hire-sarah-jeong-labeled-racist
I only briefly looked into the Sarah Jeong situation, but the outrage didn't feel authentic to me. I don't feel like this was "hey, this really hurts my feelings," I felt like it was more along the lines of "she is allowed to say that sort of thing yet I got banned for calling Leslie Jones a gorilla, this is totally unfair." I feel like probably only the kind of people who are mad that they got banned for calling Leslie Jones a gorilla are genuinely upset that Sarah Jeong didn't get banned.
-k