It's in the phrasing, then. Telling someone to "start a company" implies something larger than a sole proprietorship. At least that's why I would assume people

It's in the phrasing, then. Telling someone to "start a company" implies something larger than a sole proprietorship. At least that's why I would assume people took umbridge with your comment. Maybe, "You're an iOS dev, have you ever considered making and releasing your own app?" would've had a different impact.