What are the real-world implications of duplicate SSH fingerprints across many devices?

There was a recent post on the Shodan blog showing that certain SSH fingerprints are common across thousands of devices.

For example, this fingerprint is common across over 250,000 devices worldwide:

dc:14:de:8e:d7:c1:15:43:23:82:25:81:d2:59:e8:c0

And this fingerprint is common across over 11,000 devices across the UK:

7c:a8:25:21:13:a2:eb:00:a6:c1:76:ca:6b:48:6e:bf

This obviously presents issues in authenticating which device you are connecting to over SSH, but what other real-world implications are there in having a common fingerprint (and hence, common public key) across so many devices?