I don't get it. If you people want to play FO1/2 so much because "it's better" for ??? reasons, then go loving jerk off to FO1/2 and leave us alone. If nothing changed between FO2 and FO4 you people would bitch about it in the same way you bitch about Call of Duty.
Well between FO2 and 4 tactics was made. Interplay was taken over by two French investors, they were going to do Fallout Van Buren only to cancel it in favor of a terrible console game. Then they decided to sell it where Troika, Bioware, and Bethesda bidded for the IP. Beth in the end won it in 2006 and did nothing until 2007 when they announced Fallout 3.
Change can be good or bad, however some parts of the formula you leave alone. Call of Duty being changed into a point and click adventure, turning Half Life into a side scrolling platform, and pacman into 3rd person horror game could all be examples of bad changes. Command and Conquer for example was at its core a base building rts, guess what happened when they axed the base building part in cnc 4?
I could go on, but the changes that beth made were the ones we didn't want.