I used to be fine with recaptcha's words, translating books to help make society better. Then one day a couple of months ago all that changed. I don't remember what site I went to, but I got one of those hidious recaptchas that make you select "all the pictures that have crosswalks in them". Or maybe it was signs. I don't know.
All I know is that after several minutes I ended out being called a bot, and unable to get into the page.
It was a frustrating experience, and entirely stupid, too, because it was something like the very edge of a sign (or maybe it wasn't).
The experience was so personal and vivid that now when I come across a site that's protected by recaptcha I actually have to consider whether or not I really care about what's on the other side. Often times the answer is no, no I don't. Recaptcha is annoying enough that it will actually drive me away from your site.
On the one hand, I think it's a cool idea, because it helps protect people by classifying images so future self-driving cars will obey signals and won't run people over (which humans are very good at doing).
On the other hand Google has become a company that's eating the world, and they're not the plucky search engine that was kind of fantastic anymore. Now they're a behemoth that builds wonderful tools and then destroys them with the flick of a bit.
I still use Google, but I'm starting to rely less and less on them for things. And if you use recaptcha, I probably won't use your site, especially if takes longer than about 10s.