My guess is that it's a game theory move.

No one wants to be making electric cars until everyone is making electric cars.

Everyone wants to make electric cars, but no one wants to step out in front.

Now that we're seeing Tesla succeed, I suspect the bit is being flipped, and a lot of companies are trying to convince each other that we should all jump into making electric cars now.

Opening up patent libraries lowers the barriers for others. It's grabbing the hand of the kid next to you before you all jump off the dock together to go swimming. It doesn't fundamentally change the nature of the landscape, but it makes it easier to get started.