What are the benefits of persisting identity?

From @JustinDrake on Tue Nov 22 2016 16:43:29 GMT+0000 (UTC)

The IPFS whitepaper states

Users are free to instatiate a “new” node identity on every launch, though that loses accrued network benefits. Nodes are incentivized to remain the same.

What are the incentives for nodes to keep their identity?

Copied from original issue: What are the benefits of persisting identity? · Issue #195 · ipfs-inactive/faq · GitHub