I suspect that default 1% donation to one developer may actually discourage code contributions and encourage forking. That is, forrestv gets all the credit if somebody submits a patch. I don't think that is intentional though.
Currently (
https://github.com/forrestv/p2pool/graphs/contributors), forrestv is by far the largest contributor, with more than 75% of the commits (not counting merges for code or content contributed by other developers which isn't free).
So it's not a problem currently: no other developer can claim having contributed meaningfully without looking like a troll. The second contributor way behind forrestv with ~1% of the commits is coblee who provided the litecoin support (which served as a base for other scrypt support). I'm not sure who gets the donations when using p2pool for litecoin, it might be coblee.
That does not invalidate my point: why make more than trivial commits if miners are being asked to pay another developer in an opt-out manner?
The P2Pool.info thing sounds like it might need it's own maintainer, for example. We had somebody asking for historical data in the thread here to set up a replacement. They may be a good candidate to take it over.