Just completed the main story line. Fun, but two things comes across as odd to me. First, why does the institute focus so hard on synthetics, and second, why are there so many humans willing to risk their lives to save synthetics ( the railroad ) ?

The synthetics aren't really explained and I find it difficult to believe that so many humans, in a post apocalyptic world, would risk their lives like the rail road does.

Sometimes people can surprise you. Especially when they go against what you think is their worldview.

read the computer logs and u will find out

1. The Institute doesn't want to risk any of their people on the surface because, God bless them, they're a bunch of pampered nerds. Hence, they made robots almost identical to humans in every way as infiltrators. They also made the Gen 1s who are dispoable kill bots and the Gen 2s which are the same but smarter/stronger.

2. The Railroad is made of people who married, befriended, or ARE Synths. It's easy to dismiss a machine like Codsworth as unworthy of protection, awesome as he may be, less so when the Synth is a hot French chick. Also, the Railroad it should be noted includes many people who aren't just Pro-Synth but anti-Institute. While some people become violently anti-Synth when loved ones are kidnapped, justifiably so, others decide the best people to recruit to destroy the Institute are those who are depended on to keep it running.

On a more serious note, there's really nothing especially complex about the Institute's use of Synths.

Everyone just seems to WANT it to be more than having spies/infiltrators.

Synths are incredibly human-like. They form memories, opinions, and goals. Enough of these human-like features, some people think they should live human lives. Others oppose this. Goals collide.

It's like anything else in life. Everyone has differing opinions and sometimes wars break out due to this.

The Institute: We'll save Humanity with SCIENCE...eventually.

Railroad: You're Science is wrong, and we're going to prove it by taking your Science, erasing their memories, and putting them in witness protection.

Brotherhood: Our Science is the strongest.

Minutemen: Why can't we work together for the greater good of the Commonwealth?

Railroad: ....

Institute: ....

Brotherhood: ....KILL THE WISE ONE!

Institute: KILL THE WISE ONE!