User imprisonment. 

The biggest thing the nostr has is interoperability between nostr clients

ZBD has purposely closed bridges to the nostr by not giving their native users their nsecs. The fact ZBD went out of their way to remove/ hide nsecs from their users doesn’t sit well and gives first time nostr users the wrong impression. Its like buying bitcoin on PayPal and finding out you can’t send off their platform. 

 That's not the biggest thing the Nostr has at all. When the Nostr gets more adoption we will see less and less weirdo crazies like us switching clients every day and more people who will just use one for their entire lives (one for each purpose at least) -- hopefully the usage will be widespread enough among multiple clients.

Also, why do you want a compromised nsec that has been in someone else's servers?