When Jacob told Richard at the beach that he didn't want to "have to step in" to show people on the island what was right or wrong, then appointed Richard to do so for eternity because "if (Jacob) didn't, MIB would"... isn't Jacob now influencing people on what is right and wrong? Even if he doesn't do so directly, he is relaying his wishes to Richard who relays them to the people Jacob has brought to the island.
How is this not being corrupt? By appointing Richard to influence people, Jacob has corrupted himself just to prove that MIB is wrong and people can think for themselves, when in fact, he is proving MIB is right because Jacob himself has just been corrupted. I know this is a ramble and may be confusing... but maybe Richard was the loophole because he is the reason Jacob is corrupt and invited MIB/Locke into Jacob's statue.