Hello there Feathercircle!
Is this sort of a backhanded compliment?
Doesn't that sort of defy the purpose of ECL then though? The idea being to try and rate the effective class level of something that is technically not a class level.
I have heard these thoughts before, and on the surface they seem valid, but I personally don't think they hold water.
How can a monsters potential CR or ECL change simply as a result of it being present more often? For a start, there is no ability that cannot somehow be duplicated by spell, item or feat anyway.
Can someone honestly tell me their campaign was totally derailed because a player could fly at will? The idea sounds unlikely...unless the entire campaign is set on the elemental plane of air and the centrepiece is the aerie of broken bridges over perilous plummets!
Theres nothing mentioned above that couldn't potentially be found within a Prestige Class, wherein I doubt anyone would make a fuss. eg. Dragon Disciple.