Your “experience” runs counter to the fact having the top level of competitive game play vacate the Alliance entirely, has a negative downward trend on the lower levels of end game content?
What a strange thing to assert that your subjective day to day experience implies, when everyone else has to use aggregation websites and census data.
This is a trend that is proven in the data; more and more, the lower and lower levels of the Alliance raiding community are being eroded, and a large factor is that the levels above them have all but died off.