Yes, there has been successful trips that he's taken tourists down to the titanic and back. However, his track record isn't rock solid. His original design wasn't rated for the depths he was going. It wasn't until a whistleblower came out (which he retaliated against by firing btw) that the submersible porthole was redesigned. Who knows if the "redesign" was actually rated for the depths he was travelling. All we know is that he "replaced" it.
This is the same person that said safety regulations stifle innovation. Yeah, regulations might slow down innovation but you know... they're intended to keep people alive. The Titan wasn't certified by any governing body to travel to the depths it was going.
He didn't fully disclose to his travelers what they were getting themselves into. People say they had to sign a waiver. There's a waiver I got to sign to a eat spicy chicken sandwich at a local restaurant joint. I got to sign a waiver to park my car in a parking lot. You think 100% of people actually read them? It's just like software terms and conditions. Scroll to the bottom and accept.