Just because someone doesn't have chat enabled, does not mean they're not sharing. Likewise because you can't browse a host it does not mean they're not sharing. Browse host & chat are unreliable, always have been. You may be able to browse someone then 5 mins later you'll not be able to browse that same host. It's virtually impossible to tell if a host is sharing or not.

Chat itself is just so hit-and-miss that many people don't bother with having it enabled. It does not mean that someone isn't sharing if their chat's off.
Even in the event of someone really being a freeloader & you blocking their IP, the next day their dynamic IP address could change & you end up blocking some perfectly innocent sharer who happens to have adopted the IP