And that's why it doesn't make it much better:
;; ANSWER SECTION:
de. 86400 IN NS a.nic.de.
de. 86400 IN NS f.nic.de.
de. 86400 IN NS l.de.net.
de. 86400 IN NS n.de.net.
de. 86400 IN NS s.de.net.
de. 86400 IN NS z.nic.de.
If nic.de. is down, nameservers in nic.de. are down. Which will cause issues for DE.