> Analysts know that the internal track will end at the associate level (or, more likely, they'd be booted out after two years with no internal promotion to associate at all) > What's interesting is that a similar thing happens after two years as a private equity associate, in that almost all PE associates are booted out after two years

Many PE shops, VC funds and banks do this because they want you to get an MBA. This is why many of the associate hiring positions are described as pre-MBA associate and post-MBA associate. Post-MBA associates are the ones that will go onto internal promotions and potentially the partner track.