How would they know you are a private user? I assume you mean you have a static IP and no untoward activity originates there. But your near IP neighbors could be probing and hacking all day long and anyone seeing your IP could reasonably think you might be part of that and be annoying with CAPTCHA.

But yeah, overall, it can be eye-rolling stupidity. Mint annoys the hell out of me with similar timidity. I just sigh and remind myself that it's good they are being cautious even if some of it is very stupid.