He extorted his way onto Council instead of putting in the years.
He was a former protege of laFortier, who headed a constituency made up of wizards from smaller countries that IIRC made up about a third of the Council but were not otherwise represented on the Senior Council at all.
So he played fast and loose to get into a position of influence, but whether he is doing that out of lust for power or a genuine idealistic desire to represent and protect the interests of people who are not otherwise represented at the highest levels, is unclear to me. (I think part of what Jim might be doing with Christos is setting Harry up for an epiphany on the "hey, this is pretty much exactly how what I am doing with the Paranet looks to people who can't see inside my head" level.)