I'm sorry, but your understanding of Masters degrees seem to be dangerously misinformed. There is a wide spectrum of MS degrees offered by US universities, from leading-to-PhD to Professional-degree-for-Software-Devs. I agree there are some who "flunk out" their quals and leave with a Masters, but the selection process for a PhD is stringent enough that this is a very small minority of all MS degrees.

Personally, a research oriented MS degree allowed me to work closely with a researcher and contribute to that research leading to paper publications and a thesis. The goal of the program seems to have been to allow people to get a taste of doing research and then move on to a PhD program if they found that appealing.