The ending of Broken Sword 4 was a bit of a letdown and Broken Sword 4 was rather bad in comparison to BS3. Broken Sword 3 was a 3d game and it was a good one.
I do not believe the problem with the 3d generation was 3d itself, the problem was that people thought that "3d" means gameplay. That is, they believed there was a difference in gameplay between a 3d and 2d game so they sought other 3d games, used them as reference and cloned their gameplay, abandoning the sense of the 2d games that came before it. In many cases they ended up with 3rd-person behind-back controls and a complete mess that meant the end of the series and the company because the "3d gameplay" abandoned alot and added little.
Monkey Island 4, Simon the Sorcerer 3, Gabriel Knight 3, Kings Quest 8 etc were all examples of a bad attempt at building a "3d game" that often meant the death of the company. So where the recent Sonic the Hedgehog for example.
Today we see how using polygons doesn't control the gameplay. Games like Bionic Commando Reloaded, Magicka, Diablo 3, Street Fighter IV are all 3d but could as well be 2d.
Considering todays 3d graphics it makes sense to build games in 3d unless you are building cell-animation cartoon-style titles. 3d is just simpler to use, easier to adapt to different resolutions, take upp less harddrive space etc.