1- The chilling effect of people being scared to click on a link that may do searches their government cares about
2- The idea that if many people used a browser add in like this, it would make surveillance of search history much more difficult
3- Google accounts getting banned
All from one silly site.
Edit: apologies, meant to reply to OP, not here. To parent, I already upvote your comment - it's pretty cool, but also scary that we now have conversations about whether we're being surveiled by our government (in the US) as a casual normality. The only difference that appears to remain is that we openly talk about our government surveiling us. I worry they'll attempt put a stop to that too eventually.
One might describe it as a social botnet: somebody convinced a bunch of people to execute some code on their computer that sent automated search queries.
https://support.google.com/webmasters/answer/66357?hl=en
"Google's Terms of Service do not allow the sending of automated queries of any sort to our system without express permission in advance from Google."
Intentionally using a tool to send automated search queries is pretty clearly prohibited.
I think anyone who wants the ability to obscure their search footprint should have it. And if you think otherwise, I'm doubly convinced it's necessary.