Don't listen to those guys, I'll give you the serious answer.

The old steel skinny frames were getting so light the UCI had to enact minimum weight requirements to put a stop to it. Besides the excessive light weights, the frames were getting so skinny that bikes would literally disappear right up riders butts. To combat this, they started to make the frames fatter. But since steel is governed by the laws of Superman, he was in no way going to allow 'steel' to be synonymous with being fat so they had to go to another material.

As for the straight forks...

Well thats just to combat the curvy backsides to keep the bike in neutral handling. If the front was all curvy , some people might unconsciously feel the desire to mount it from the wrong end creating the inverse of the original problem.