Yep. This idea is spec'd at https://meta.wikimedia.org/wiki/Research:Account_creation_UX/CAPTCHA. Doing a short removal experiment got support from Chris (Steipp, works on security) but was definitely a touchy subject. 

Our alternative idea is to support adding a refresh button to the CAPTCHA wherever it appears (so both account creation and where it appears when saving an edit). This is pretty much already built and working, and you can try it on our Labs instance http://piramido.wmflabs.org/wiki/Main_Page. We just need to make sure it's incorporated well in to our new account creation look being worked on for MediaWiki core. 

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