Given the aggressive response from this company, it is less likely that it will become the target of any security researchers in the future (who wants the hassle ?). That by itself makes their app less secure in the long term. Also, who'd want to support founders with this "I will destroy you!, even though you helped me improve my system" mentality ? I wouldn't be surprised if this startup dies off from this info.
Kudos to Cooper, Miles and Aditya for seeing this through.
Alternatively, it will attract the attention of less-noble researchers who won't bother with responsible disclosure rules — they'll just leak data or tinker with the system. But I agree that well-intentioned security researchers will be less likely to look into this platform.
Kudos to Cooper, Miles and Aditya for seeing this through.