I am a professor of electronics and I think that the commercial success of a micro-controller and its popularity is linked to its simplicity of use and to the number of peripherals in the device. If, the MSP430 is a winner from the second point of view, as regards the first is definitely loser. You can not lose more than 5 minutes to set properly a UART port (eUSCI in this case). You can not miss a day of work to fix the baud rate!
Finally, it is useless to give 1000 documents of 500 pages each, that no one will ever read, but would be appropriate to write a single document that summarizes everything and is easily accessible. These reasons decree the success (commercial) and the popularity or less of a micro-controller.
Thank you.
Caliano