The decentralized Finance technology are new and varied. That's the reason why many of them are attached. It's also due to the lack of safety measure implemented by those DEFis.
As we grow towards a universal platform and solving issues, Defi would be one of the most secure way to handle our finance, fast, efficient and secure.
If that technology can attract more people to come, I guess there will one or more group of people who want to try to test the system, so they know if the platform have a bug or not. But I agree that Defi will grow better in the future if the team can do hard work and fix the problem although there is no guarantee for them not to get attack again.