I would argue that Edison, Bell, Ford and the like all changed the world significantly. Did they change it for the better? Who is to say?
Mandela, King and Ghandi certainly were overt in their motives to change the world for the better, so in many ways they may be more visible targets, but Bill Gates, Tim Berners-Lee, and the whole current raft of inventors of Twitter, Facebook, etc. have certainly changed the world.
RMS changed the world by an idea that became a movement — but it would go no where it he didn't attach them to some excellent software, practicing the idea throught [cue Ghandi "be the change..."].
Jimmy Wales changed the world, again by idea + software.
Diffie & Hellman changed the world, in a much more fundamental way. The possibility of end-to-end security didn't visibly touch people the way Wikipedia did, yet it put all our lives on a different track. OK, that was scientific discovery, not programming but it's way closer to programming than to political speeches.
Bitcoin changed the world, again idea + software. It's unclear at this moment if a cryptocurrency changes it much — or for better — but the very fact that it's here, without anybody's permission, is novel.
The very ideas that building stuff can change the world — and that giving it away maximizes your impact — are a major change in the world!
[gross simplifications and omissions in all of the above.]
Without technology we would still live in the stone age. Politicians don't matter. Nothing grand in a hunter-gatherer band leader ordering a fight with another band.
Democracy is not "technology", nor does it necessarily require technology. Your claim implies that democracy didn't change the world. Are you serious about this?
When you mention people who change the world I picture Mandela, King, Ghandi and other political leaders who made their lives and the lives of their societies better. A piece of software can not achieve something of similar scale and importance because... There's nothing like an idea that becomes a movement.
I don't want to start a flame and I feel that this conversation is taking the wrong turn so I won't post other replies.
Anyway, nothing personal against you or the dev.
Best of luck with everything