Ok, you want to go there? Let's go there....
I already saw that post. And I looked into it... let's go over their "help":
>>"Really Simple CAPTCHA requires that GD and FreeType PHP libraries be installed on your server in order to create CAPTCHA images. If you are not certain if they are installed, ask your server administrator."
First off, the system should be able to recognize that there are some prerequisites that it requires that are not installed. It does not do that.
Second, the system requires an additional plugin called "Really simple captcha" - which is listed as "being written for CF7" so why the F doesn't CF7 simply include it? So you have to install two plugins to make one simple system work.
So I installed Really Simple Captcha (which I'm now going to give a bad review too as well because of all the time I've wasted) and it didn't make any difference. CF7 still didn't work.
Furthermore, the author says a variety of things are required but doesn't tell the person how to really tell if things like GD or FreeType are available - just pawning that off on "ask your administrator". That's lazy. As a coder, it's not difficult to find out if those subsystems are available. This is a crappy-written plugin. It's certainly not worthy of a lot of stars when there are much better plugins that don't require such convoluted processes to make such a simple feature work.
Furthermore the help documentation itself has errors:
>>"Contact Form 7 creates a temporary folder and stores any CAPTCHA files there. In most cases, the location of the temporary folder is wp-contents/uploads/wpcf7_captcha, but it can be different depending on your settings."
There is no such path called "wp-contents" - it's actually "wp-content" as everybody knows. The author cannot be bothered to be precise with important things like file and path names.
The system is badly written, badly documented, and does not work.