For all the conventional reasons: the victim of the abuse deserves sympathy, and that abuse shouldn't happen.
But also because we seem to be placing the blame for the abuse on the service, not the abuser. And that's sad because instead of being able to just make interesting stuff and put them online, we are being forced to consider "what's the worst possible thing that some evil bastard could use this for?" and prevent that. Again, like the responsibility is on us to not make things that could be used for evil, rather than the responsibility being on the evil bastard to not do evil things.
And ultimately, it means we'll go the same route as Omegle; it's just easier to not make stuff than fight this misallocation of blame. The world will be poorer without random quirky websites. Evil bastards will do their evil offline still, so no-one will be better off. But apparently that's what we want. It's so sad.