It's not just "purists" (whatever that means) who complain about CAPTCHAs. A very significant number of users find them difficult or impossible to use. I include myself in the first part of that group of users and I hate the evil things. They aren't necessary, either: I've never needed to use a CAPTCHA to deal with spam or misuse on my site. Some thorough filtering and validation handles it fine.
Amazon Fire HD 8 review: A brilliant combination of function and value – with one massive caveat