Well, in the Superman Returns novel version, Sor-El was one of the people who helped create the Kryptonian gov't. That, to me, makes it seem like the house of El is pretty darn influential.
Influential, yes, but King? Jor-El's warnings were pretty much ignored - although we don't know if Jor-El's warnings were heeded to create New Krypton.
I am leaning toward it having been an existing industrial colony and the high houses did take Jor-El's warning seriously, but felt he was too much a revolutionary to trust. (I'm still working in this.)
