Except it's not random. Mechanics always inform role play, and role play informs mechanics, any player who has been playing for any length of time should know that. Do you have a problem with clerics getting their spells through gods, or fighters performing their maneuvers through swords? If you don't have a problem with those, why do you have a problem with a sorcerer using powers via dragon blood, or any other heritage. You just don't make any sense.
The complaint is that the thing they scraped together right before GenCon is incomplete. People have to think a little. They wanted something new to show for GenCon, but since they are not done with the fighter and wizard yet, that means that whatever they show will be incomplete. Considering PAX Prime is in just over a week, it will likely be incomplete for a little while. They have already shown way more transparency than with any other edition, which i praise and enjoy. What you're all getting is a rare glimpse into the design process, and many of you may be learning for the first time that the design process is a weird, disfigured, and often slow mess that slowly begins to resemble a completed product.
I'm all for critiquing what is there, but don't complain about what's not there.
And by all means, please everyone listen to the podcasts. They explain a lot about what's going on and what's planned.
The problem is, the way 3e did it is that they couldn't measure the power level of TWF. Every time they made an ability that added damage, they had to worry about the fact that it could be doubled with TWF, which oftentimes meant an ability was either overpowered with TWF, and balanced without it, or balanced with TWF, and a weak without it. That's not a good way to design things.