I personally dislike them for several reasons:
#1 They are pain with tor or any other browser without javascript or hard to solve. At least for me. If I want to visit a site with Tor and its blocking me because of Tor with a captcha I just gave up and stoped visiting these pages. Its a collosal waste of my time to try and solve them. Its mostly cloud flare AFAIK.
#2 They are a pain to solve for honest users, but not for those that already invest time and money to spam the forum with nonsense. Yes, it would make the spam more expensive, but I dont think it will stop it. It might however stop new users that do not understand and do not care why the captchs had been put in place. We would essentially reduce the newbie jail without the need to post, but instead to solve captchas. The 360 seconds rule already annoy people.
@More moderation:
I dont see a reason for more staff, at least not durring NA/EU times. Most of my reports are handled quickly, esp. those regarding newbies. I think its the same for those form NA.
Offtopic/joke section:
Edit: Sho does a good job you know
Im no longer in account "deleting" business.
SC2 is considered to have a high skill ceiling, but it's artificially inflated by forcing people to do micromanagement activities like injecting larvae, managing hatchlings, things like that (APM, or actions per minute). It just ends up being frantic and kind of a drag, and makes it more difficult to focus on the fun part, the strategy.
I hear this was greatly reduced with the latest expansion. Cant confirm though as I blow my battle.net money on HotS.