Movies reuse assets all the time too. For example, not only did the Indiana Jones movies shamelessly reuse the same character asset for the main character...they reused a character asset from Star Wars! They just gave him new clothes and a hat and hoped we wouldn't notice!

In all seriousness though, the "asset flipping" issue is a different thing than simply reusing code and assets. Of course game designers are going to reuse stuff...it's called not re-inventing the wheel. And something else to keep in mind is that these days the art budget is higher than the software budget.

But this goes way back. Just look at Super Mario 2...JP and US version. One simply made newer levels using the exact same code and assets. The other just re-skinned an existing game.

As far as cookie cutter titles, this has been going on as long as there has been video games as well. When Space Invaders and Asteroids came out it seemed that all any other company would make was a clone of those games. Another great example is the Sonic games. It seems that every other platform game that came after it was just a copycat collecting random things floating in the air for no particular reason at all other than Sonic having rings, and the Sonic Rings might just have been copying Mario's coins. Or all the early 3D platform games that just copied what Mario 64 did...some even going so far as having you jump into things to get to the levels(Gex, I'm looking at you).