Re: Jonathan Blow, I don't think it's a stretch to say different/better tools can have a profound effect on the industry and resulting games as a whole. As someone in games, quite a lot of software has had far-reaching impact that influenced games on a noteworthy level. Speedtree, Zbrush, and the substance package have basically defined modern AAA art assets. And while the major public engines have had a profound impact, even things like Source mods, RPG Maker, and Game Maker have had a profound impact in terms of enabling development of breakout indie hits or introducing people to game development as a whole who are now in the industry.

So I don't think it's a stretch to say a performant alternative to C++ with a game engine out of the box could have an impact which has broader reach than speedier development of his next game.