Long story short, besides the DEI forced shit, Mary Jane lead, niggers in power armor everywhere, the final and biggest nail in the coffin is a complete lack of attention to the source material. They basically erased the entire lore of Fallout 2, New Vegas, and the NCR all in one go. But don't worry: Todd Howard assures us it's all canon. Don't waste your time, if you were in fact thinking of doing so.