Analyzing the Plot of Mass Effect 3

Independent game developer Gareth Fouche offers an extensive writeup on his own website analyzing the plot of Mass Effect 3, and he doesn't sound very pleased with it. Spoiler and swearword warnings apply.
But, within 30 minutes of gameplay it is revealed that your scientists have been digging through the Prothean archives on Mars and have discovered something, plans for a super-weapon that the Protheans conveniently got to 99.9% complete, design-wise, but didn't actually manage to use. And the discovery of this ancient blueprint is made at the most dramatic moment imaginable.

If it had been made later, well, everyone would be dead. If it had been made a year prior, the information would have been disseminated already, you wouldn't have the '˜fight Cerberus infiltrators on Mars' bit and Cerberus wouldn't have been able to '˜steal' the information.

The Reaper invasion has been foreshadowed for 2 games, you knew it was coming and so their arrival has the weight of that anticipation behind it. They clearly built the games knowing the invasion moment was coming. But I'm guessing that they didn't have exactly how everything was going to be resolved it nailed down though, which explains why there is no foreshadowing of the Crucible or the Star Child. Gotta leave maximum flexibility for changes at a later point.

Relying on this kind of plot device is a sign of a poor writer, poor planning or both. There have been two game plots recently that relied on the (and then the magic device fixed everything!) ending, Starcraft 2 and ME3, and both times it annoyed me greatly. And it annoyed me that gamers, as a whole, don't get upset about these things. We get crap writing in games because we accept crap writing in games.