When you are browsing TOR hidden services, the TOR system already provides end-to-end encryption, so another TLS layer is redundant. It is in fact counter-productive, because one of the goals of TLS is to de-anonymize the server. It makes no sense to go through the trouble to set up a hidden service and then get a certificate from a certificate authority which tells the whole world who you are. Well, you could use a self-signed certificate (some people seem to do this, otherwise Orchid wouldn't explicitly disable verification), but a certificate not signed by a certificate authority can be replaced by a man-in-the-middle so it only provides protection from a passive eavesdropper.
However, when you browse normal websites via TOR, TLS is even more important than usual, because the exit node can eavesdrop on your traffic in cleartext and even manipulate it. There were already exit nodes spotted in the wild which exploit this by inserting advertising or even malware into websites their users browse or to sniff logins for popular websites. Using TLS makes this impossible, but only when used correctly (which means with certificate validation. An unvalidated certificate could be from the malicious exit node).