Jhananda,
I guess that is quite likely considering the fact that all religions start competing with others as they become organized. Then the religious leaders kind of have to come up with some doctrinal teachings that their path leads to higher goals than everyone else...
When we examine religion and civilization we see the two are closely associated. Both religion and civilization are expressed in art, architecture and literature. Then we have to ask, who has the wealth to build religious institutions, build civil structures, and fund scriptoriums for the reproduction of religious literature? The answer is one and the same. The ruling class has the wealth and power and motivation to build religions, institutions and literature that back them. When we examine the leaders of religion, who do we find in charge? In most cases they are members of the ruling class.
Regarsing monks, I think there are forest monks who practice deep meditation including develiping certain psychich powers. But since city monks are in charge of the overall religion, forest monks tend to stay underground.
Regarding your hypothesis that forest monks get realization. Do we see that they have supported or contributed to a dialog on jhana and the other topics that we discuss here. While there are a few that we have quoted here; nonetheless, in most cases we have had to correct their erroneous assumptions, such as Ajan Brahm claiming the first jhana is a manifestation of a glowing sphere, which he calls a 'kasina.' Whereas, the suttas do not describe this phenomena at all. So, my conclusion is all branches of Buddhism are hopelessly corrupt as is all other religions.