"Legitimate" is relative here. I would count you as using unusual software to hide your actual source address. Not a huge concern because if you're doing that, I assume you also know how to move around to avoid getting blocked.
In fact, the ability to move to a different cloud on short notice is also part of the CAPTCHA, because large cloud-based botnets usually can't. They'd get instabanned if they tried to move their crawling boxes to something like DigitalOcean.
I used to run an X instance in the cloud that I would sometimes browse websites from. It sucked but it was also legitimate.